Hard question, since indeed every case is different.
First of all it depends on who power abusing you. If it's a single player or if you're a target of a dominant guild.
In first case I would try to talk and find a solution, but sometimes it is simply impossible so I would ignore it then. On my server it is also possiblity to "report" power abuser to dominant guild and if this person often disrespect other players then he'll be hunted.
Second case is a little bit more complicated. It depends what kind of dominant guild it is. Bona is third server where I play. On each server I had an opportunity to meet dominant guild and I can see the huge difference between them. On the first server "dominando" was simply stupid. Everything was forbidden, you could be hunted because you killed Ferumbras Mortal Shell. They often asked for payment and after they got it, they power abused you again. When you became their target, there was nothing that you could do. In this case I suggest to change the server :P
On Bona dominant guild is way different than the one mentioned before. Here we've got a clear rules and not many restrictions. So when player is hunted he usually can make a payment and it solves the problem.
Okay, so as you can see there is not many options to solve it. Payment (if possible) or change the server. Worth to mention if we can ask Cipsoft for help.
I'm afraid we can't. Power abusing nowadays is a part of Tibia. It's our choice whether we want to play a game with such features.
As I remember Cipsoft reacted in similar case only once, when dominant guild destroyed whole server. If we're talking about single player problem they won't do anything, because it is legal.