No appeal shall lie from the judgment passed ex parte against a defendant who has not appeared, or from a judgment against a plaintiff by default for non-appearance. But in all such cases if the party against whom judgment has been given shall appear, either in person or by agent, if a plaintiff within fifteen days from the date of the Collector's order, and if a defendant within fifteen days after any process for enforcing the judgment has been executed, or at any earlier period, and shall show good and sufficient cause for his previous nonappearance and shall satisfy the Collector that there has been a failure of justice, the Collector may, upon such terms and conditions as to costs or otherwise as he may think proper, revive the suit and alter or rescind the decree, according to the justice of the case. But no decree shall be reversed or altered without previously summoning the adverse party to appear and be heard in support of it.