Dear Will,
I write to thank you for your excellent service last week when you coded the ABS system on my BMW Z3 roadster. You achieved what a BMW main dealer failed to get right even though they are supposed to be the experts, and at a fraction of the cost. Your personal, courteous and prompt service was also very much appreciated.
I have requested a refund from the main dealership, which they so far have refused to give, despite subsequently offering me a credit note for the full amount which in itself is an acceptance of liability, but nevertheless insisting I should spend the money with them! Naturally I did not accept their offer and I have given them 7 days to pay or I will commence proceedings against them in the small claims court.
Rest assured that should I ever need specialist help with a BMW in future, you will be the first person I will call.