It's also possible the person in charge of responding to Trustpilot reviews is not aware that they made a "final decision", perhaps that's why they are asking for the ticket number
The support agent knows that the accuser's account was flagged by the sportsbook provider "betby" and knows the exact reason behind the flag "multi accounting". So, it's obvious that he is well aware of all the details of this case.
My assumption is that they are trying to look friendly and willing to help since this accusation is posted publicly on a well know reviews website. Not saying they are scammers and OP didn't indeed break their ToS, though.