If you have tried to upgrade your armor by using Defense Cubes and you failed an enchantment, you have a couple options;
1. Buy a Reducing Toolset from an NPC Merchant along with a Reducing Cube of the appropriate rank. Combine the broken armor, the toolset and the cube in your Combination Box. This will result in recovering about half of the cubes already put into the armor and the toolset back.
2. Buy an eRepair from another player or the Item Shop. Combine the eRepair with the broken armor in the Combination Window and you will get the armor back in the same condition it was in before the failed enchantment.
If you are asking about the current event drops that randomly come from kills (Rotten Leather Armor/Shabby Cloth Costume/etc), that armor is for a short term event. You take the armor that was dropped and combine that with a Reducing Toolset in your Combination Window and you will get some components back along with your toolset. This event is ending on June 2nd. Further details can be found at http://rappelz-forum.gpotato.com/viewtopic.php?f=2&t=949452