If it's advertised that he would receive a cash back for his play, then he should receive a cash back even if it's $1, he is entitled to it. Personally, I HATE online casinos but if the OP wants to play in an online casino for a laugh or whatever, let him, he's not hurting anyone. IF the cash back was advertised, he should get it, end of story.
$200 - $2,000,000 does not matter.