With the introduction of 4Story/Gates of Andaron Patch 3.5 you will see a new item dropping from monsters:
[Coin of Endendros}
This item is designed to be used with a future feature of the game. You will be able to exchange these coins into Bonus-Premium-Cash at some point in the future.
Right now this feature is not yet implemented. Unfortunately we were not yet able to disable these items completely.
Thats why we can only tell you the following:
Keep these items in your inventory, item stash or cash-shop inventory.
Once we activate the Bonus Feature you will be able to use these items, as they are supposed to be used.
Your 4Story/Gates of Andaron Team