You can do it by logging into the sites and enter your profile. I think it took me about 10 minutes to wander through menus and log in on different versions of the same site, but at least I managed to cancel my subscription. Although they don't seem to make a big deal out of it if your credit card information is invalid either. All that happened to me was that I had to pay for a one month subscription before I was allowed to buy a renewal. Hardly something that will bother you who sold yours.Gorilla Gunk said:My subscription is set to renew soon but I sold my Xbox and recently switched banks so I look forward to all the emails demanding I change my account info so they can charge me.
OT: I know how you feel, I don't even have the power adapter to my Xbox around so paying for this service is a waste. I bought the gold membership mainly because I got a good deal on it. I also doubt my network is good for online matches.