This problem doesn't require a technological solution. A legal solution is perfectly adequate. In Sweden, for example, you can inform a company of your wish to

This problem doesn't require a technological solution. A legal solution is perfectly adequate. In Sweden, for example, you can inform a company of your wish to cancel a service by email or letter or phone call or...probably there are more options I'm unaware of. Given such a right, you never need to play the games that companies want you to play.