I agree with @bigvalboy . We all get to set our own terms here - clients and therapists. The phrase I use when communication has headed in the wrong direction is something like "Seems like we're not a good match, thanks for answering my questions, peace." No anger, no accusation, no argument. Once or twice a therapist has said "Sorry, I apologize for my tone.." or something lke that, and we get back on track. but - most of the time that's the last text I send.