A couple of hours later, I received a response:
Thank you for sending the required documentation over.
As we have now received the requested documentation and verified your identity, we were able to complete our investigation of your sportsbook activities.
It was concluded that your sportsbook activity breaches our Terms and Conditions and your account will be closed as a result.
Is there more to this response from them? or this is all of it?
Did they happen to mention which part of your sportsbook activities have breached their T&C? It seems vague if that's the only reason they have given.
How can I get my winnings back?
You could try and file a complaint in casino guru, that might help them notice your concerns and have them resolve it.
https://casino.guru/complaints/all