this is a clear scam. i dont even want to go into explanation. any site that bans you for multiple account is a scam site. if they want to ban , they should do it before the persons deposits or withdraws. i bet you if you depo 1btc and loose they wont ban your ccount they will expect you to depo more and loose more. win and they will come up with that trash
If this is indeed multi-accounting, the case becomes more complex at a stroke:
Many casinos (also very well known like Sportsbet) explicitly exclude multi-accounting in their terms and conditions. You agree to these terms and conditions as soon as you register on the platform. If you still act against the terms and conditions and create multiple accounts, the probability is high that you will be banned. There are already some scam-accusations in the forum, which turned out to be cases of multi-accounting.
But I agree with you completely: Examinations always take place when you want your money back and not before. The risk is borne solely by the customer, who is then also obliged to prove that he is not running a multi-accounting system.