I'm really sorry this happened to you, Dave.
It's incredibly frustrating to deal with big companies, they have all the advantages over us "little people". Don't give up, be persistent and make noise. They wouldn't like bad publicity (like a letter to your local paper, etc.). We're lucky that one of the major news stations in Seattle will often broadcast consumer issues regarding big or dishonest companies called "Problem Solvers". They get results. I hope you can get it resolved.