You can have a backbone of steel and they will still do it. The only thing you can do is take away your time and financial commimttments to them. you can also report them to authorities if they are breaking any laws.
Thats about it. You can't make someone do something they don't want to do, there are leverages you can make, but for most situaions if they are going to run over your decisions, you can choose to leave or let them leave.
