Not what I wanted to hear

Sounds messed up, but.....
My Medtronic pacemaker was replaced "under warranty". Had issues with settings staying put and drifting out of spec. The pacer would either work when it wasn't supposed to or not work when it should.
I would ask if they'll cover it under warranty. Worse thing they could do is say no.
What is the battery life of your device? Medtronic is saying 10+ years on my pacer. I understand the two are not the same.