AOL/ Talk.com Changed my lon distance without authorization, obtained my credit card info from AOL and billed my credit card after I refused to pay ripoff Clearwater? Internet

Talk America used to be affiliated with AOL, who has since severed all connections.
My long distance service was changed without my knowledge, by Talk America. I never received a bill from them, (I was later infromed that I had been receiving e-bills) until about six months after my service had been changed. The bill was for around $450.00, and the said my account was delinquent, and I needed to pay immediately. Of course I called them promptly to inform them that I never ordered their service, and refused to pay for it. After much deliberation, they told me a telemarketer had called and obtained authorization. I still refused to pay, hung up, and thought that would be the end of it.
The next month my credit card statment reflected a $450.00 charge from Talk.com. Furious, the first thing I did was dispute the charges with my credit card company, then call Talk.com again. They offered me no answer to how they had obtained my card number, or who had authorized the change in my long distance carrier. After two months, my credit card company took the charges off of my bill, so I was happy and didn't think anymore about it. Now these charges are back on my credit card. Of course I will dispute them again, but how can this happen? My AOL account was billed to the same credit card, so I suspect that during the affiliation between the two companies, my information was traded. This is illegal, but upon further investigation I learned that what happened to me is quite common, and that there is currently a class action suit by the state of Florida against Talk.com.
These practices must be stopped. How can this be allowed to happen?

Scott
Charlotte, North Carolina