I am sure Rollbit will never do such an unprofessional act of restricting certain regions and without informing ban those accounts. Of course, the gambling site has the right to disallow players from any county to their site but if they want to add more countries to their exclusion list, they should tell gamblers in advance and also, they should give ample time for their players to withdraw their money, if any on the gambling site.
I see a common pattern is after one account has problem, some other accounts appear to claim a same problem. I am not Rollbit staff so I don't have internal database to judge but this pattern is suspicious. Like one account in a farm that aimed to cheat Rollbit so it makes sense that after one account was detected, terminated, it will cause domino effects to other accounts.
The more the casinos are transparent, honest, and customer friendly, the more popularity they will gain over a period of time. Casino should not play dirty games only to get hold of the gambler's money unlawfully.
It is not about Rollbit that is big enough, trusted enough.