this has happend to me many times, you place a bet, it will say bet accepted .. or it will say bet accept on the screen, then a pop up appears saying bet was not accepted, contact customer services.
then the number you bet on wins .. for example I was casually playing roullete on pragmatic play.. this happens alot on pragmatic play.
then i decided Wth let me put 4 on 36,, instead of 1 on the line.. or instead of smaller usuall bet , I put 4 straight up on 36.. then wheel starts spining.. then all of a sudden they take off your bet and send that message. guess what ! you wont win nothing../ and a few times they dont even refund the 4 back into your balance.. in under just 1 year. this has happened to me around 4 times on pragmatic and 2 other times on another shady provider i think playtech or something.