Clear Clearwire Consistently far less internet speed than what I'm paying for. Palatine, Illinois

I've been a customer of Clear(wire) since October, 2008.  I had no connection speed issues until I moved to Mountain Home, ID in December 23, 2009, which is 45 miles from Boise, ID.  I called customer service prior to moving to confirm they had service in that town.  I was told that they did and I would have no problems.
When I did move, I immediately began to have connection speed issues.  I was paying for 3mbs per second and was only getting no more than 1mbs or less consistently.(never anymore than that)  I've called on numerous occasions with no resolution, and their normal response after doing some troubleshooting was that it must be my computer.(even though I now have a brand new computer)
When I check the "coverage" map it doesn't show any coverage for my 3g modem.  Only coverage for 4g mobile.
I want to discontinue service, but they threaten to charge me a cancellation free which I can ill afford as I'm on SSDisability.  I am aware that Clear has a history of many, many complaints elsewhere, and apparently they don't care as it seems nothing is ever done about these type of complaints.