Indeed they have the chance but the question is, do they take that chance? The money involved or expenses they use in their operation and promotion is too huge to mess up by cheating their players. So I do not think that reputable casino cheats their player through algorithm because as far as I know they can be verified by professional gambling inspectors.
They can change the betting algorithm to set a low chance of winning so that the gambler will lose no matter what the bet is in that game, so it is very important to choose a popular casino site and fair play over other casino sites that may harm the gambler. But we know the specific problem of the OP's losses, it's possible that he lost due to being greedy in the game and not setting a funding limit for gambling.
if you won't stop playing, then, you will indeed lose your funds. some people will only stop when they lost all their bankroll. and then, they will accuse the casino of cheating and all. of course, there's always house edge for the casino to survive. what do they want? go home with huge winnings every time they play?