Your account can only be deleted through the username you provided to the support or their representative here. Your account can't be deleted without at least having to get a trace of your account either through your mail or username, for me I would advised you should send your details to the forum representatives since he is mostly active here, because sending mails could take days to have effects on your account.
Dr.Osh issue might be a little bit more complicated than that. His issue is not with support’s response time.
Blocking his account can be done quickly as soon as he provides his username, as the casino's OR confirmed above.
Dr.Osh is asking for his personal information, which he submitting while completing kyc,to be completely deleted. As I said, this might be a little complicated as the casino's privacy policies clearly states