Speedo issue.

[Tony V8Avant77]

My car is a jap import brought in 2016. It’s an S4 B7 Avant. The clocks have been changed but the Speedo reads all wrong. It was like this when I bought it in Oct 18. Previous owner didn’t tell me until I landed in Manchester to pick the car up. Anyway when I’m doing 70 the Speedo is reading 100! I’d have thought if I was doing 60 and the clocks were still km it would read 100. The faster I go the more wild it gets. It’s been plugged into Vagcom and doesn’t seem to have done anything. Audi want the car for the full day which is a pain in the !Removed!. Anyone got any ideas or a way to sort it through Vagcom?