Classmates.com Widespread Consumer Fraud Internet

I just discovered fraudulent "membership" charges from Classmates.com,  an online company that contacts you via email to tell you that an old classmate from high school is trying to get in touch with you. I discovered charges of about $40 going back a year. I emailed the company, but received no reply. My payment company basically told me it was probably my fault. I googled Classmates.com and found a huge list of people also receiving membership charges going back years, charges they can't seem to make go away. Don't know what to do next. Credit card company told me to call back if they charged me again. Classmates.com obviously makes their money this way. 

Susan