Sounds like dementia - all these things are symptoms of it. Since you are presumably just talking on the phone to him, let him talk , sympathise, and then hang up and forget it.
There isn't any treatment for this - at his age you will only have a fairly short time to put up with it. So let his accusations roll off you like water off a duck's back. You'll be fine. My mother was like this - I'd just say yes, yes, then hang up and go on with life. It's all you need to do.