peugeot diesels are prone to problems resulting from use of supermakret petrol. Onc the problems have been fixed insist on a full service, paid for by them, then avoid supermarjet petrol like the plague. I promise, you won't regret it.
As you have had the car for so long I think you have very few rights, though it is reasonable to expect them to provide a courtesy vehicle at their cost, so I think they should re-imburse you this cost that you have incurred, but I suspect that they will argue over much more. I would suggest that you ask the dealer to warranty the vehicle for another year out of goodwill.