I wouldn't trust poloniex either.
At list I know who they are and where to sue them
Poloniex has Privacy policy and proper AML/KYC and doesn’t hide itself
Well, using Poloniex is better then imexchanger.pro - better from 2 bad ones
Try to contact BestChange directly in bitcointalk and see if they can help you somehow.
I did, no use at all, they send me standard replies without seen the issue
They protect or cover this scammers from imexchanger.pro, why do you think the do it any idea??