Hello @shirleymac Sorry to hear of the challenges with your husband and the phone. You are not alone as my wife had the same issue -- and she loved having her phone too! We had to attack this issue in phases according to what my wife's mental capabilities were at the time.
Sadly, with so many folks disconnecting their landlines phone scams are far more prevalent on cell phones than before and the 'do not call list' has become almost irrelevant with cellphones, number masking, and robo-calling. Personally I get some kind of scam phone call at least once or more each and every day.
In the early days we utilized the Contacts feature in my wife's phone. Added in family and friends. She then understood enough to know if a name did not show up on her phone when it rang she was not to answer it -- an easy lesson since I was able to show her I was doing the same thing with my phone. Unfortunately this did not last long.
As hard as it was we move to having 'phone time' and 'no phone time' during the day. Phone time was a set time when I knew I would be with her. No phone time was when I was not, during meals, newspaper time, coffee time, etc. I used the ruse of the fact our son was doing the same thing with our grandsons so we were just helping set a good example. I then let our family and friends known when to call if they wanted to reach her. This lasted a bit longer.
Unfortunately when this was no longer understandable for her I simply had to take the phone away. Hard, but way easier than having to tell her not to drive, not to walk anywhere alone, taking away her credit card, checkbook, etc. In the grand scheme of all the independence she lost in her disease journey her phone was a speck rather than a mountain of an issue.
Wish I had more to offer, but send strength, courage, and peace!
Thanks Scott @IndianaScott - great advice. You are so right about cell phone scams being more prevalent. Nothing seems to get rid of them including putting every number that calls on a block list - same people calling but just using different spoofed numbers. I am filing away your phone time advice for use with some of my customers who have a lot of problems dealing with it.
John