You may ask, why on earth did you go to imexchanger.pro instead of poloniex, for instance?
I wouldn't trust poloniex either.
https://BestChange.com has a feedback system, but if you leave a negative review it will be removed, i saw it myself happening with my claim
We already know about their terrible feedback system, and I think they announced some changes in near future.
I wouldn't blindly trust any exchanges listed there after I saw many cases of people having problems with them.
There are much better alternatives that never ask for any kyc, like eXch for example.
I would really appreciate help or advice on how to get my money back?
Try to contact BestChange directly in bitcointalk and see if they can help you somehow.