It's a nuisance, takes forever, and you will be switched through to the retention department. Just be passive and say "no." Don't bother getting argumentative because you will be cut off and spend another hour getting back to where you were.

Do not fail to pay by cancelling or otherwise using a generated CC #. XM will refer a $10 matter to a collection agency. Sooner or later you will pay and, at a minimum, you will have a "referred to collection" note on your credit report.