Poor workmanship

I took my vehicle for a service at Car Service City at Fairview in Gqeberha. They gave me a list of things that I need to attend to. So we arranged with them to do it for me. One of the things that needed to be attended to was the seal on my fuel tank because it was leaking. A day after they replaced my seal, my tank started leaking petrol. Trying to get hold of them after hours, I couldn't get hold of any of them. On Saturday I phoned the North End branch and I got hold of the manager and he assisted me. This happened over Easter weekend. He took the tank off and informed me that the outlet on the pump is broken and needed to be replaced. He tried his best to get one, but couldn't due to it being easter. On Tuesday he phoned to say they got a new one and they are going to charge me only for the pump. Now its costing me more then expected. Fairview wants to offer only a 10% discount or a R500 discount. I lost about a half tank petrol and had no vehicle for the weekend. They could've prevented the problem if they phoned me to say they think the pump could be the problem and not the seal. I won't recommend them to anyone.