Seems this is getting nowhere with BelleRock support (no surprise there, it's a non-standard problem, and they are just firing off the standard "cut & paste" responses).
There are two further channels to try,
1) Casinomeister, both the BelleRock rep & the Pitch a Bitch service (try the rep first & give it at least a week)
2) eCogra, although you should not simultaneously use
PAB, or continue to post until eCogra has given a final responce.
Hopefully, you should be able to come to an arrangement whereby the casino can verify you by discussing with you what you could provide.
One little known trick is that you can get your bank to write a formal letter confirming your details, which would include your name and address. As an American though, this might prove tricky, as you can hardly tell the bank WHY you need this - you will have to make something up, such as loan application, or to rent a holiday property.