No services rendered after two month delay

I have a household generator, and it began leaking diesel or oil a long time ago. I contacted GP Lawnmowers who supplied the unit. They came out several times and claimed to have fixed the leak by tightening some nuts. The leak always persisted though. Eventually they decided to take the unit in. I didn't hear anything for a month. I phoned them and they couldn't remember what I was referring to. But they found it, and agreed to deliver it to me. Another month passed. I phoned again, and they claimed to have fixed the leak. When I told them it's been 2 months, he was upset and denied it, claiming I made a mistake and it was only 1 month. After having received the unit back, I discovered that it was still leaking. They also scratched it quite deep.<br> I may add that 2 years ago when they first collected it for a service, the load truck reversed into it.<br>