I know its hard that they had poke out your gambling addiction but why you cant just let it pass and save up yourself on lots of hassle on trying to fight
out your rights?
Move on and stop gambling if you really wanted to and dont put up yourself into hassle and much effort to prove out that you are right.
To be honest, this is a lost-cause for OP's side where he still continues to believe that fighting this battle would yield him rewards. Again, I do think that stake somehow and impliedly acknowledged their fault in sending out any promotional email in their side. By blocking your accounts, that was the last step in order to secure the idea of any possibility of you coming back.
While you may show any evidence to prove to the contrary, I mean at the end of the day, what does it prove anyway? While I also fully support your decision of quitting, fighting this kind of battle relatively proves that the lingering feeling of gambling may soon convince you to do it again.