Review of Mayne Automotive Onehunga

I purchased 2 x $189 coupons for free labour. They gave me free labour on a service, but still charged me $230 for an oil filter, fuel filter and oil. They took all day to service the car after saying it will be ready by 11am (I dropped it off at 7.30am).
They also failed the warrant for a faulty ball joint and quoted me $250+GST to fix it. I phoned another mechanic who said it would cost $150 maximum and when I took it too him he said there was nothing wrong with it and gave me a warrant!!
They're obviously trying to make money by finding problems that don't exist.