Ok, I just did my 3rd XM subscription renewal. This time they wanted about $155 (up from last year). As I have for the past 2 years, I called to cancel. The first operator told me the ZWINBACK promotion for $77/year had expired. She tried to talk me into a 3 yr commitment with a small discount. I said no, she referred me to the cancellation guy ('Matthew') who also checked my file and offered me the $77 deal for the year.
ONLY DIFFERENCE: This time he said it had to start today, rather than waiting for my 6-21 expiration and adding on from there. So I lost 5 days, but still got the $77 deal. I decided to take a bird in the hand rather than calling back in 5 days.
My recommendation is to wait until the day before yours expires. Remember, the 1st operator you talk to will NOT give you the deal. Only when you turn down all other options and they refer you to the cancellation operator. At least it has consistently been that way for me for 3 years now.
[I know this is not a Kappa item per se, but couldn't find another category that fit]