Welcome to the world of dealing with SEAT .
For most people owning a SEAT is something they do day in day out with no issues at all.
But when you do get an issue like the OP then you turn to SEAT dealers for
help and actually find they haven't got a clue what to do or where to start.
SEAT uk wont take notice of any indepandant report or what they say.
Unless you can prove to a SEAT dealer the issue with your car you will be banging your head against a brick wall for a very long time.
Just out of curiousity ask your dealer about cam follower wear , his reply should tell you all you need to know about the dealer network.
To the OP bear in mind this , if you do get an Engineer from milton keynes and he reports back that your car is mapped you may be asked to stump up the bill for their
help.
So if i were you i would re think my approach.
Your car is out of warranty , so if i were you i would be going to a very good indy , they may take a week to find the fault but at least you can talk to them and feel confident that they will actually be able to fix your car.