Laverton Car Care

I went to this shop to fix air conditioner of my car.
I dropped the car in the morning and asked them to give me a quote before start repairing.
I ringed three times around 10:00, 11:00 and later but couldn't get in touch with the guy working on my car.
I called again later and the guy said everything has been fixed, I need to pay $240 for that and after I said OK, he added that's excluded GST.
When I came to pick up my car he can't tell me what parts has been replaced other then he had regas the air conditioner.
And finally about 2 weeks later the Air conditioner became weaker and about 6 weeks later not produce any cool air and I have to fix it again.
My theory is they just regased the air conditioner of my car for $240 and didn't border to fix the leak.
Personally I will never go there again.