Olymp Trade - application fault

application fault and solving the issue and saying it was my fault to check when i am trading.,
*)before trade it shown the comission * dollors but when i trade it takes nearly **% of my money.
when i ask customer service they are saying based on the market it takes comission
*) if comission takes based on the market then at the time of trade i done another trade also with * dollor for that it takes normal comission and
*) after i tried with *** dollor trade again it take ** % comission
like this i lost my money.
olymp trade becoming fraud app now.