I have found out for myself that I will stand up for myself then walk out. Usually it has been a build up over time & I have thought through the situation in my head before getting to the point of having enough. By that point I say my final peace then end it permanently by walking out permanently or ending communication. I only remember 4 times in my 70 years where this has been necessary but it has worked each time & by that point they don't get another chance. I will be civil to them if encountered again BUT they will never be allowed back in my inner circle