NSS Magazine Service Center fraudulent ripoff business Nationwide

I received four charges on my credit card for NSS magazines. I never ordered any of these magazines so I decided to call the 800 number which was listed next to the charges on my statement. It was an automated attendant which answered the phone, I entered my six digit reference number which appearred on my statement that the attendant referenced. The message was they didn't show the reference number on file so they asked for my credit card number. I did not want to offer that information over the phone and I was unable to contact any human customer service reprenstatives.

How did this company get my credit card information? How do I stop these charges from re-occurring and how do I get my money back?

Lynn
Mechanicsburg, Pennsylvania