I was charged $55 and signed up for a monthly subscription to Justanswer.com without my permission.

I asked the online Xfinity assistant for help with an email problem. I was sent to Justanswer.com and  told I would be charged $1 which would be reversed. I was then charge for a $55 monthly recurring subscription to Justanswer.com without my knowledge. I also didn't get my email problem solved by Justanswer.com. They just gave me all the obvious possible suggestions. I feel Justanswer.com is an unethical way to solve issues with Xfinity applications. How can I get technical questions answered without being scammed by Justanswer.com?