Product: Credit card or prepaid card

Back in XXXX of this year I ordered a couple of bottles of vitamin supplements from a company called XXXX, tel. no. 
XXXX, using my Citi XXXX XXXX XXXX XXXX MasterCard tel.no. 
XXXX This was a special offer to receive the supplements as a free trial, I only had to pay the shipping and handling of {$10.00}. 
Within a couple of hours I received a call from the representative of XXXX encouraging me to extend my purchase to some kind of club, " don't worry you can cancel at any time '' he told me. I interrupted his spiel, thinking that this was all probably some kind of scam, and told him, " Listen to me, I can see where this is going, this is some kind of scam ... I want you to cancel the entire order NOW, the free trial and any additional orders. '' And that's the way the call ended. 
About a week later I received the free pills that I had cancelled anyway, and I was charged for the shipping and handling only on my credit card, but I also received an email that the account was cancelled so I didn't think I needed to worry about any future charges. 
But about a week after that ( I'm sorry I don't have the exact dates ) I got a credit alert call about my Citi Card, asking me if I had made a recent charge for {$180.00}. I said absolutely not, I made no such charge on my card. The Citi Card representative said, " Don't worry, we will take care of it, we will cancel your card and issue you a new card and those charges will not be on your new card. '' I asked them who the charge came from and they replied, " Some internet company .... but don't worry about it, we will take care of it. '' I expressed my appreciation for their diligence in protecting me from fraud. 
They did close the old account and issued a new card. The {$180.00} did not appear on the new card but the {$10.00} shipping and handling charge carried over and I paid this bill. I thought that would be the end of it! 
But about a month later, on XX/XX/XXXX I believe, I got another alert from Citi Card that {$180.00} had been charged to my NEW card! I asked them what was going on, and they referred me to their investigative department. When I explained how this charge that had already been dismissed had reappeared on my new card the representative said that they were sorry but I had been ''taken in '' by the ad for the free supplements, that IF I had read in detail the long, arcane " terms and conditions '' fine print of the free trial when I had ordered, ( which he said, and I quote, " NO ONE EVER DOES '' ), I would have seen that the pills really weren't free, and because I had checked the " read terms and conditions box '', I had essentially played into that companies scam. He said, and I quote again, " IT HAPPENS ALL THE TIME ''. I explained to him how I had cancelled the order within hours of making it and that I had never authorized or received any additional product from the company. He said, sorry, because I checked the terms and conditions box there was nothing he could do about it. 
So what this tells me is that Citi card continues to do business and accept charges from a company that they KNOW are scamming their customers. As the investigator said " IT HAPPENS ALL THE TIME ''. They could easily stop allowing their card to be used by that company. 
Instead they ENABLE, COLLUDE WITH, and even worse PROFIT (! ) from the scamming of their card holders. As far as I am concerned that makes Citi XXXX XXXX XXXX XXXX MasterCard part and party to the scam! 
I cancelled my card and told them that I was never going to pay this bill, because they were part of the scam by continuing to accept charges from a company that they know very well is scamming their customers : " IT HAPPENS ALL THE TIME '' as the investigator said.