I called Motherhood's 1-800 number and they gave me a number for Parenting Mag. The number is 1-877-604-7858. I called the number and the rep. I got was Marlene. I told her I was to cancel my subscription. She then told me that she would cancel it and if I received any more bills to disregard them. Try it and see what you get. Just be sure to write down who you talk to just in case they don't take care of it.
Good Luck and I hope this helps some of you with the same problem!
Re: Parenting Mag. Follow Up
I also regretted saying yes to that "free magazine" thing. I just wrote on the bill to cancel and sent it in. So far so good, I have not gotten anything else or any other bills.