Was there a rupture that caused this rift between you two? It seems like if you've had a relationship for 34 years, and there was trust there, that there must be a reason other than the money that is behind this conflict. You've been paying the copay for 5 years. Why are you bringing it up with him just now?
I'm not saying he should have been charging you the copay or trying to bill you for phone calls, but it just seems like something relational has happened for it to come to this.