(a) If a defendant in a civil action fails to appear or otherwise notify the magistrate court within the time limits prescribed by section five of this article that he wishes to contest the action, the magistrate may render judgment as justice may require as follows:
(1) The magistrate shall render judgment by default only upon affidavit or sworn testimony reflecting the nature of the claim, whether or not it is for a sum certain or for a sum which can by computation be made certain, the defendant's failure to appear or otherwise notify the court within the time limits prescribed by section five of this article that he wishes to contest the action and supporting the relief sought. In the event the plaintiff's claim is not for a sum certain or for a sum which can by computation be made certain, the court shall require such further proof by affidavit or sworn testimony as is necessary to determine the propriety of the relief sought.