Soccer question

Has the referee in a soccer match ever overturned his decision? I don't think I've ever seen that happen. And, yet, every time a card is handed out, be it yellow or red, all the players on the affected side swarm the ref and crib big time. I don't understand what's the point given that even the players know the ref is not going to change his decision once he has made it. In fact, like cricket, if fines were levied whenever the players showed dissent, I think their match fees would not suffice, and soccer players would have to pay out of their pockets!