unauthorized charge from NSS Magazine on my credit card

I received my credit card statement and found an unauthorized charge from NSS magazine for $50.00. I phone in that 1-800 number on the statement right away, but it was some kindof an automatic response, no real person to take care of a problem. That shows they really plan to rip-off people by not having a way to describe anything to a real person. So I phone my credit card company, and all they said to me is that I need to work thing out with NSS, but noonw is picking up the phoneto work thing out with me there. The most strange part is that I am an AOL member, and all I remember is that one day in May this little offer icon pop up on my screen, and I accidently click "OK" just that one click then the next day I got an welcoming email for a new subscriber. I emailed them right back that I had never meant to subscribe for anything, and they also email me to say sorry that the magazine is not working out for you. And that's all it was, I've never got any single magazine and I though that was it, and never thought about it until today I got a charge of $50.00 on Aug 13, exactly 3 months after. And that's all their stupid automatic response told me that this charge is due after the end of the trial period. But I've never try any one magazine, not even realize that I was on the trial period. It's a complete rip-off, and still now that I could not get in touch with any person at NSS magazine, only those machine running all the same shits all over again.