During a recent service on my 2010 Hyundai i30, the dealer told me that the digital instrument binnacle display was flickering and needed to be replaced under warranty. I was happy for the work to be done, but when I got the car back I noticed that the mileage had been reset to zero. The dealer tells me it was not possible to replace the instrument display without resetting the mileage, but did not warn me of this beforehand. I am now worried my car will look dodgy to any potential buyer as the clock shows 22,000 miles less than its supporting paperwork. What can I do?