My 10 year old Smart Forfour lost its oil while driving recently. I stopped immediately and arranged for recovery to my local garage with my recovery provider. After a 10 day wait for a replacement sump the car was repaired at my expense. At the breakdown companies request I sent them a copy of the repair invoice to (I thought) prove that the car was repaired and roadworthy.

To my astonishment they have now sent me a bill for £138 saying that this fault is damage to the underside of the vehicle and is something that could be claimed from my insurance company. Having paid for my recovery policy and for the repair to the car where do I now stand with respect to this unexpected bill from the breakdown company?