Getting money back from Optionbit

I opened an account with Optionbit … they offered a $200 bonus … i did not accept this bonus but it was added..

i invested $500 US in this startup account … i am not able to get my funds back.. they will not answer my emails… only to ignore my questions..

i am not trading there but my account is reducing… it went to $928 US then down to $728 US now at $708 US..

it appears they are using my account to trade…

what can be done to get my funds back and eliminate this trading platform from trading …