Start the dispute, but stick with it and constantly remind them to investigate!
I bought a PDA that was listed as "new in box" when it arrived it was a brown cardboard box with no charger, manuals etc just the PDA and on top of that when I got it charged and turned on the language was set in French!! Well peed off, started the dispute after unsatisfactory responses from the seller. Paypal never sorted it out, after two months I got back to them to ask what was happening to be told there was no dispute!! I persuaded them that there was, so they were looking into it, and a month later nothing, so I chased again to be told I was too late to lodge a dispute and that it was tough!!
I eventually sold the PDA through Ebay for more than I paid thankfully, having listed it genuinely! Made me giggle that the buyer was a chinese person living in Aberdeen that wanted a french language PDA!!