Trip/mileage display?

Hi, I have the vehicle listed above Corsa c. For some reason my car shows a random mileage and trip mileage a few minutes into a drive. This trip mileage and the mileage before never changes, I've driven the car over 2,000 miles, and these figures don't change. Of course, the original mileage comes on when I first get in. The other thing is the trip mileage that appears with the correct mileage resets to zero within minutes too. I've tried resetting the trip meter etc., even the switch ignition off push the trip meter and then turning it on, still the same issue...does anyone have a solution to this as its really frustrating. Thank you. The random mileage it shows is always 026270 and trip mileage 88.1.