Surrey-based Wilson's Automobiles & Coachworks has been expelled from Motor Codes' code of practice for service and repair.
Wilson's, a car supermarket which sells marques including Nissan, Renault and Peugeot, did not progress conciliation to the code's standard.
When a customer complains, there is a conciliation process to complete, to ensure all parties are satisfied.
Chris Mason, Motor Codes director, said Wilson's refused to partake in this process which included non-payment of a conciliation fee.
The site was given a first warning in September before being referred to Motor Codes' Independent Compliance Assessment Panel (ICAP).
Mason said while it was obviously disappointing that a garage had failed to meet the code, it was “only one subscriber out of nearly 5,000 reviewed”.
The expulsion was a result of the first meeting of ICAP which reviews the performance of the code and compliance of its subscribers.
It was decided unanimously to expel Wilson's.