(a) Every retail installment contract shall be in writing and shall be completed as to all essential provisions prior to the signing thereof by the buyer, except as provided in subsection (f) of this Code section. The printed portion of the contract, other than instructions for completion, shall be in at least six-point type. The contract shall contain substantially the following notice in clear and conspicuous type:

"Notice to the Buyer

Do not sign this before you read it or if it contains any blank spaces. You are entitled to an exact copy of the paper you sign. You have the right to pay in advance the full amount due and under certain conditions to obtain a partial refund of the time price differential."

The contract shall contain the names of the seller and the buyer, the place of business of the seller, and the residence or place of business of the buyer as specified by the buyer.

(b) The maximum number of payments and the amount and date of each payment need not be separately listed if the payments are stated in terms of a series of scheduled amounts and if the amount of the final payment does not exceed by more than 50 percent the scheduled amount of any of the preceding installments; in such cases, the amount of the scheduled final payment shall be stated as the remaining unpaid balance. The initial date for the payment of the first installment may be a calendar date or may refer to the time of delivery or installation.

(c) A retail installment contract need not be contained in a single document. If the contract is contained in more than one document, then one such document may be an original document applicable to purchases of goods or services to be made by the retail buyer from time to time.

(d)(1) Notwithstanding any other law, the seller under a retail installment contract may charge, receive, and collect a time price differential, which shall not exceed 13¢ per $1.00 per year on the unpaid balance.

(2) The time price differential under this subsection shall be computed on the unpaid balance of each transaction on contracts payable in successive monthly payments substantially equal in amount for the period from the date of the contract to and including the date when the final installment thereunder is payable. When a retail installment contract is payable other than in successive monthly payments substantially equal in amount, the time price differential may be at the effective rate provided in this subsection, having due regard for the schedule of payments. The time price differential may be computed on the basis of a full month for any fractional month period in excess of ten days. Notwithstanding the other provisions of this subsection, a minimum time price differential not in excess of the following amounts may be charged on any retail installment contract: $12.00 on any retail installment contract involving an initial unpaid balance of $50.00 or more, $7.50 on a retail installment contract involving an initial unpaid balance of more than $25.00 and less than $50.00, and $5.00 on a retail installment contract involving an initial unpaid balance of $25.00 or less. As used in this subsection, "unpaid balance" shall be determined in accordance with Section 226.8(c) of Regulation Z promulgated by the Board of Governors of the Federal Reserve System pursuant to Title I (Truth in Lending Act) and Title V (General Provisions) of the Consumer Credit Protection Act (Public Law 90-321; 82 Stat. 146, et seq.) as the same existed upon its becoming effective on July 1, 1969.

(e) The seller shall present a completed copy of the retail installment contract to the buyer at the time it is signed by the buyer. Any acknowledgment by the buyer of receipt of a copy of the contract shall be in clear and conspicuous type and, if contained in the contract, shall appear directly above the buyer's signature.

(f) No retail installment contract shall be signed by the buyer when it contains blank spaces to be filled in after it has been signed, except that, if delivery of the goods or services is not made at the time of execution of the contract, the identification of the goods or services and the due date of the first installment may be left blank and later inserted by the seller in the seller's counterpart of the contract after it has been signed by the buyer. The buyer's written acknowledgment, conforming to the requirements of subsection (e) of this Code section, of delivery of a copy of a contract shall be presumptive proof in any action or proceeding of such delivery and that the contract, when signed, did not contain any blank spaces as provided in this subsection.

(g) The seller under any retail installment contract shall, within 30 days after execution of the contract, deliver or mail or cause to be delivered or mailed to the buyer at his aforesaid address any policy or policies of insurance the seller has agreed to purchase in connection therewith or in lieu thereof a certificate or certificates of such insurance. The amount, if any, included for insurance shall not exceed the applicable premiums chargeable in accordance with the rates filed with the Insurance Department; if any such insurance is canceled, unearned insurance premium refunds received by the holder shall be credited to the final maturing installment of the contract except to the extent applied toward the payment for similar insurance protecting the interests of the seller and the holder or either of them. Nothing in this article shall impair or abrogate the right of a buyer to procure insurance from an agent and company of his own selection, as provided by the insurance laws of this state; and nothing contained in this article shall modify, alter, or repeal any of the insurance laws of this state.

(h) If the buyer so requests, the holder shall give or forward to the buyer a receipt for any payment when made in cash.

(i) Notwithstanding the provisions of any retail installment contract to the contrary, any buyer may prepay in full at any time before maturity the unpaid balance of any retail installment contract and in so paying the unpaid balance shall receive a refund credit thereon for such anticipation of payments. The amount of the refund shall represent at least as great a proportion of the time price differential after first deducting therefrom an acquisition cost of $20.00 as the sum of the monthly time balances, beginning one month after prepayment is made, bears to the sum of all the monthly time balances under the schedule of payments in the contract. This method of refund upon prepayment is commonly referred to as the "Rule of 78" or the "Sum of the Digits" refund method. Where the amount of the refund credit is less than $1.00, no refund need be made.

(j) In a retail installment transaction involving the modernization, rehabilitation, repair, alteration, improvement, or construction of real property, the buyer may be charged for and there may be collected from him or there may be added to the cash sale price the reasonable fees and costs actually to be paid for construction authorizations and similar permits issued by public agencies.