(a) Any proceeding brought under this article is a civil action governed by the rules of civil procedure. The mother of the child and the alleged father are competent to testify and may be compelled to appear and testify.

(b) If in any paternity action an answer has not been filed within the time required by Chapter 11 of Title 9, the "Georgia Civil Practice Act," the case shall automatically become in default unless the time for filing the answer has been extended as provided by law. The default may be opened as a matter of right by the filing of such defenses within 15 days of the day of default, upon the payment of costs. If the case is still in default after the expiration of the period of 15 days, the plaintiff at any time thereafter shall be entitled to verdict and judgment by default, in open court or in chambers, as if every item and paragraph of the complaint or other original pleading were supported by proper evidence.