Oh wow, so BK8 didn't owe OP any money and yet there's a scam accusation?!
As for the closure of the account, any service has the right not to serve users especially those who don't comply with the ToS. It can be location-based, attitude-based*, etc.
*I have a service business myself and have shown the door for assholes as well.
Anyway,
I can guess what the result of this case:
The sportsbook provider detected your betting activity as abnormal and notified BK8 to close your account.
Remember that it doesn't matter what casino you play, as long as you use the same sportsbook provider, you are still the same person. Make sure you didn't have a bad history with that provider or abused the system too much.
My educated guess is really accurate no?
User was detected abnormal in JS provider, hence have been taken action to suspend and return all her remaining wallet amount.
...
This member most probably got the account in other website and found abnormal, therefore she is flagged as abnormal by JS provider without any betting.
Yep, classic!