Thankfully you were paid back.
I wouldn't recommend anyone else to use BetOpen still because it has been demonstrated that they basically neglected this case until their ICO is around. If there was no ICO they probably wouldn't have paid anything back.
As Darkstar suggested, i think that signing a message that is holding at least say, 50BTC of user funds is necessary. Otherwise they are essentially running a ponzi scheme, aka your depsoit is paying others withdrawals.
I'm still waiting for my money 1.800 BTC
Please wait till after ICO and try again. I don't think they have it.
Bad idea. If this was a scam, then after the ICO the scammers have their money and have no incentive to pay back anyone. @sedna, open a scam accusation just like OP has done, so you can get your money back (hopefully).