Bob,
I recently had a number of issues with XM Radio billing, not the least of which was the fact that they had a collection agency calling me for a bill which wasn't even due yet. After going round and round a number of times with them, I cancelled my service.
I did some online checking and, lo and behold!, I found that it wasn't out of the ordinary. I found a very large number of complaints about XM on this website, (I also posted my "tips" about them, too!).
http://gethuman.com/XM_Radio-customer-reviews_912.html

Roland Babineau
The only true Harbour Lights dealer left in the world and the ONLY retailer in the world authorized to sell Harry Hine's lighthouse collectible line!
http://www.thecapecodstore.com/harbor_lights.html