I don't think it makes sense for a casino as well-known as Stake to cheat its user for $22. They have a good reputation and there must be some kind of mistake. The player could have accidentally pressed the wrong button without even noticing it. If it was a bug on the gambling site, we would have heard about such situations more than once. But if the player is 100% sure of his right then he definitely need to seek justice.
^ Definitely right and you have a good point there, I think they will not scam that very tiny amount for them, $22 is almost nothing for them and I think they will not scam that small amount. There could be many factors that happen and I think calling them a thief is not necessary because you are not proven yet. So for now, the best thing that you can do OP is approached them nicely reading your issues, I don't think they will not listen to you in that way but there's nothing wrong if you will try them.