After using up an hour of my time I finally cancelled our SiriusXM service. They turned of our radios immediately even though we had several weeks left on our subscription. They did this so I might call again and get hammered with special deals to enroll again.
A note to our Congressional delegation. Any business in the US that provides account services through the internet must provide the ability to cancel such services in a simple and effective way. Introduce that bill and win thousands of votes.