(a) Any security interest taken pursuant to a retail installment contract or revolving account shall not be taken with respect to clothing, softwares, and other nondurable items. Each payment with respect to a revolving account shall be applied to goods and services as follows: first to unpaid time price differential or finance charge; then, as to goods purchased on different dates, the first purchased shall be deemed first paid for; as to goods purchased on the same date, the lowest priced shall be deemed first paid for.

(b) Nothing contained in subsection (a) of this Code section shall prevent the parties from agreeing in writing for the payments to be otherwise applied; provided, however, that this Code section shall be construed consistently with Part 2 of Article 15 of this chapter, the "Fair Business Practices Act of 1975." Nothing in this Code section shall be deemed to authorize any act or practice which would otherwise be deemed unfair and deceptive under Part 2 of Article 15 of this chapter, the "Fair Business Practices Act of 1975."