Does anybody know what to do if I join a money league and the person is not paying out the money he supposed to or return it when I asked
Lotta shady "commissioners" doing that this year. If that happened to me, I'd report cyber fraud (provided there was some level of a contract in place before you sent them the funds via PayPal, Venmo, whatever). Once that step were completed, I'd also report to SDS to see if there's something that can be done to their account to not allow them to commission any leagues, too. It's just bad for everyone.
You're SOL my guy.
this is on you. SDS has no help for you here.