I don't care if a company does out source it's subscription renewal process, it is still their name and their product that is being represented. I feel it is a direct reflection on them and their business ethics. When ever I get annoying subscription notices after I have asked the company to stop I simply fill the self addressed stamped envelope with confetti. I write on the renewal card: PLEASE DO NOT CONTACT ME AGAIN in bold letters. The confetti gums up their automatic letter opener so my envelope gets the attention of a real person, and my bold writing gets the message across.
I told my mother I did this and she was shocked, she said she thought she raised me better than to be so mean. But I saw my dad taking confetti pieces out of the shreader machine the other day when a batch of junk mail came arrived. Might be mean, but I come by it honestly.