They said BC Game is VPN friendly, so I assume that can't be your issue. Your issue might come from you making use of BC Game while you are from and based in the UK, which BC has closed their service with.

You can either try to contact their support and see if there will be any remedy to your problem, or if it's for you to be allowed to pass KYC, that will not be possible since UK users are no longer allowed.

Selling of accounts and transfer of ownership—is that even legal under gambling law?