If anyone pay you to remove the negative trust, then other users will start doing the same, and that kind of extortion doesn't work at all on this forum.
Just by doing that, you will get a lot of negative trust, so, by that action you make a step from the victim side to the bad guy side, and that's not a smart move at all, if you had a problem with the casino you should tell your experience and try to fix any inconvenience, but asking for money is not the way to resolve issues.
Don't waste your time explaining it to him. Having this idea and thinking this might work is something special, never seen something like this in here.
I mean, what he is thinking??
Sure you can be unsatisfied with a casino site, I was also with some in the past, that's just natural. But going this route would have never crossed my mind even the slightest.