I cancelled my subscription to XM Radio a couple of years ago and it was such a hassle I shared my experience here. That post continues to generate comments and Google juice. First, the latest comment:
“Even though my credit card expired, they continue to send me bills. I have called numerous times to cancel but they refuse to do it. Instead, they continue to bill me through the mail and call relentlessly for the money. I am on hold now for at least 45 min. This is a problem that every XM subscriber should be aware of.”
More than 10 million search results and the 2nd one (right after the company FAQ page) is a bunch of folks with horror stories about the company.