SiriusXM - Lost connection to subscription -- Help

I have a 2011 Prius III with Navigation and SiriusXM subscription. Everything with Sirius was working fine until a month ago. I am able to receive channel 000 and 001 and all of the free channels when SiriusXM is doing a promotion.
I have tried countless resets. I have spent hours with SiriusXM technical staff. I have taken the car to my dealer. All with no luck.
Is there a reset that can be applied to the radio unit that will restore it to factory settings? The dealer has not been able to do that.
Any thoughts would be appreciated.

 

Thanks for your suggestions, but alas, the subscription is fine. Sirius folks have reset the account and I've sent countless reset signals to the car, using the their web page and using the tech support folks. The dealer folks have not been able to find anything wrong with the radio. I've asked them if they could perform a reset - I don't know this for sure, but my experience with computers tells me that memory can be corrupted. I haven't been able to locate anything to confirm that in my web searches, though. I thought that here, someone might have had a similar experience.

 

Thanks for the information, Don. I haven't tried a complete cancellation - new account, login, password, etc. Everything but that... I'll give that a shot.