Every 6 months, if you don't want the EC item you have, you can refund it for full price. After that, you cannot refund another EC item for 6 months.
EC Refunds would not hurt the income of the server, due to EC not costing actual money, so don't try to make an invalid argument. I do not support refunds for any other items in the game. The lovely staff needs some sort of gain from Era.