If you want to quit therapy, simply stop going. Don't harrass you therapist. That's rude and stalkerish. Do the mature thing and simply tell her you will no longer be returning to therapy. She can't force you to attend therapy unless perhaps it is court ordered. If that is not the case, all you have to do is stop going. If you want to make it official, write a formal letter stating your intent to discontinue therapy and telling her that she cannot contact you. Send it registered mail and be done with it. Playing games is NOT the adult way to end your therapy.