Jim, the only thing I would change is the last sentence. Your validation is a little over the top so it could almost sound sarcastic. Maybe rather just say 'I'm sorry it took you by surprise, I thought I was clear when we spoke about it that I would take you of the plan at the end of the month.' "Suggested" sounds vague - like there was room for misunderstanding. Was there?
I would not have cut off the phone without an e-mail. You have to cover yourself with her so you can't be made to look bad.
M 16 yrs, WH62, P54 3 adult blended kids EA 11/13, BD1 6/14 PA fall 14, BD2 2/15 Piecing 2015, BD3 12/15 Separated 4/16 WH moved OW in 5/16 Divorced 6/15/17