Admiral breakdown not recommended

My son broke down so called Admiral. They sent out a "roadside engineer" who established that the coil had gone. He did not have a coil with him so called someone from Automania.who said he could fix it at a cost of £30. I thought this rather strange but was told by Admiral that the contract was between my son and the engineer if we went ahead with the repair. My son had to get money from a cashpoint and the coil was replaced by the engineer from Automania. 10 miles along the road my son broke down again on the M3 in roadworks. We called Admiral again who said they would send another truck but by the time they arrived my son had been picked up by the Highways Agency. My husband had already set off from home because he was concerned for my son's safety. The second tow truck then took my son's car to our local garage following my husband all the way. A two hour journey turned into eight hours. Our garage then replaced the coil but thought the one from Automania was not new. Indeed the receipt my son signed in the dark was made out to a different name and different registration. 7 weeks on I am still fighting to get a refund for the part and compensation for my husband's petrol. I was also told by my garage that best practice when a coil goes is to change the plugs. I provided evidence including photos of the dodgy coil and a scan of the receipt but am still waiting for Admiral to contact me. I will be cancelling my breakdown cover with them as soon as this is resolved.