Hopfull

I have the AVIC f900bt that has come up with (system is starting up please wait) at first I tryed up dateing the fime ware. When this did nothing I called the place that installed it for me and they told me it had to go back the Pioneer. I have been told that it has a problem on the Nav board and that it most be replaced at a cost of £270.00 plus VAT is there any thing I can do so not to have to pay out more money on this unit I have only had it for 3yrs. Any help GREATLY APECIATED