I successfully cancelled my XM service today (5/16/13), using this toll-free number I found at the GetHuman website:
When the automated announcement answered, I hit 1 then 2, which gave me a real person immediately. I told her I needed to cancel. She asked for my phone number associated with the account, and then transferred me back to the U.S. I spoke with a very nice woman by the name of Tracy, and I told her I needed to cancel. She asked why, I simply said 'financial reasons'. She politely offered a few choices to try and remain, I declined. She then cancelled my account, told me how much my credit card refund would be, and gave me a confirmation number. All-in-all, very painless, took less than 10 minutes from dial to hang-up.
Anyone need a SkyFi2 in good condition with the home & car docks?--
Well, I'M not The Kirk, tell ME what your function is!