My Dad has Alzheimer's disease

Dad called this afternoon. Told me he went and picked up his insulin at CVS and it cost over $168.  I ask him who ordered it and told him that I did not and the cost should not have been that expensive. He said that CVS just called telling him to pick it up.  After spending over and hour on the phone calling CVS and the insurance company, I discover that the prescription coverage had changed.  CVS was no longer a primary provided for the HMO he has. So the insurance was only paying half of the cost. Couldn't get dad to understand.  Getting dad to understand anything is almost impossible.