Scam with Live Chat

A few minutes ago I was speaking too what I thought was live dhat with Xfinity. After going through a series of questions and answers she recommended a phone call va chat with my problem. Then she said there would be a $5 charge, full refundable. Never heard of that before but since I got the chat through Xfinity I did not think about it. Turns out to be a scam. The five dollars was 48 dollars and my apple account refused it. In addition, I tried another credit card and they refused its as well. NO idea how they snuck into chat line but they did!