Cancelling my service

I am trying to cancel my service, however when I called in today I was told I had to give 60 days notice, which is news to me, and that I'd have to pay 75% of my remaining contract which ends in September.

When I signed up I asked the sales person multiple times if I would be charged if I needed to move outside of Comcast's service area and he said no each time.  The contract would be voided if they are unable to provide service.  I feel lied to.  Looking through these forums it appears I am not the only one.

The billing person I spoke to would not transfer me to a supervisor or manage to discuss the issue.  I got her to agree to have a supervisor call me back within 24 hours.  However, having worked in a call center when I was younger, I am skeptical it will be a supervisor, it'll just be another customer support rep because the actual supervisors and managers don't want to deal with customers.

At this point I'd recommend my friends use DSL rather than put up with Comcast.  The connection itself was shotty at best for a six month span.  I ended up upgrading to a 50mb connection and still only get 10mbps at some points.  The sales people lie, the customer support people are not helpful, and the product itself is sub par.

I want to speak to someone who can help me resolve this issue.