Volusion.com lied!! Said my new website could connect to my current shopping cart but it can't Internet, Texas

When I signed up with Volusion, I was told specifically that my new volusion website would be able to connect with my current shopping cart which was working well for me. After I got the site set up, I was told that I couldn't use my current shopping cart but had to use theirs.  When I looked into using theirs, they said my monthly fee would be $80 instead of the $20 they originally sold me.  I tried to cancel and they refused to refund the $120 is spent on the template, the $80 is spent on an SSL cert, and the many $20 monthly fees that I bought. Worse, when I protested, they said they would review my case but instead closed the case the same day and never got back to me. (They said they would get back to me in 2 days). It's been more than 10.