Not sure if this will help anyone in future, but I had un-asked for work done on a car of mine and the garage refused to give me the car until I paid. I told them to send me the invoice and we can argue later. As to not releasing the car, if they keep it, it amounts to theft! It is legal my car and it is up to them to try and get outstanding bills paid through court. You have 3 months to pay an invoice, regardless of what they say. Got my keys when I started phoning the old bill.
Secondly, My omega wouldnt start one day after it had been stood a while (turned over well, but didnt try to fire). I suspected the fuel pump and checked to find no fuel flowing. I asked a friend with an omega if he knew where I could get a cheap pump and he said he had the same problem with a slightly flat battery. Charged mine up and got fuel flowing again andd started straight away. I am sure someonre knows why, or will say a coincidence, but slightly flat batteries have stopped the fuel pump on 2 diferent omegas now (both petrol).