I thought about creating a new number but that is probably not the easiest choice in many cases. So the operator wasn't able to recommend anything else, yes ? Then I guess there are not many options what to do. 

I was thinking that if it's not a lot of casinos where you play , maybe unsubscribe from such things but I don't know if that will help 100% either, that's just what I was thinking. 

I hope you'll be able to sort it out somehow.

Not even in any sister casinos ?

Then I am not sure what else I could advise. I know that a player also wrote this once, but it was sent to his email. Also from casinos where he was not registered. But eventually he managed to block it. If even the operator can't help you, then all I can really think of is to get a new number. 😕