EU law would support your opininon that its been maintained as long as the garages used are VAT registered and genuine parts have been used.
Id also ask which part of a seat
service could have or would have picked us something like this.
However it is out of warranty and in my excperience Seat are poor. I had an issue when i brought my cupra, which was 2.5 years old from a
seat dealer, paid for and receipted for a further year
dealer warranty and got nowhere.
Im not so sure what this part is thats failed, is it something that can fail like this? or can it be damaged during
servicing? is it even checked during services? could a part thats going to fail be detected or would it look ok then fail immediately?