Blue Cross Blue Shield of Arizona review: Crossover

I had BCBS on my wife's account before I could get Medicare. A year and a half later I dropped it to purchase my own policy with another company. I informed BCBS I was cancelling. I assumed they would take it off my Medicare account--which they did not. Here it is almost seven years later-still on there-still receiving a bill (that is denied because I don't have them). I've spent countless hours with them to get this off my Medicare account,with promises to do so.
It's still there. It's been filed with BBB-nothing happens.
This whole process with billing slows everything down, and a waste of time, paper, and postage.
Bottom line--they don't care