My 1.9 pdi diesel Octavia is on variable servicing.

It had its first service at 19K and it second service at 38K.

But now, at 46K, the maxidot display reckons it needs a service in 800 miles.

Before I tackle the dealer, any ideas what could have gone wrong?

The oil used at the last service (according to the invoice) was Mobil 5W-40 for which I was charged

Is it 12 months ago you had the last service ??????????

They may have done a dash reset.