Are We Buy Any Car fair in reducing their offer for 'part service history'?

We bought a new Hyundai ix35 in May 2014. We had it serviced in March this year as we thought it did not need servicing until 20,000 miles. It's only done 20,600 now so it was not serviced earlier. We were selling to We Buy any Car today, but they say we should have had it serviced after two years rather than wait until 20,000. Is this correct? There was no cost saving in not having it serviced earlier, as we had a service plan with the car. WBAC wanted to reduce their offer by £600 because of this as they consider it only had part service history.
Yes, they are correct. I personally would not touch a car that had not been serviced at least every year or every 10,000 miles whichever comes first (unless, of course, I could buy it for buttons).
Answered by Honest John on

Ask Honest John