Poloniex margin trading BUG

[salvolol]

About two days ago i did a margin buy order on poloniex and until that it is ok,but after reaching the target price (i was on STR/BTC market) of 0.00000715 BTC the order has not been executed but a loan has been opened and i cant close it and also cant close the margin position. Now im paying fees without the chance of using the coins or take them back,i also contacted their support but they are not responding about this serious bug.What do you think i can do?