Not satisfied with my service with this branch at all

I took my car in for a 50000 km service to Toyota McCarthy N1 City because it was convenient for me as it closer to work. I asked them to check the aircon as it is not working properly,they quoted me on re-gasing it. Prior to this I took my car to Halfway Toyota Ottery for the previous services. On my return to pick the car up after the service at Toyota MacCathy at N1 I was told they could not do the re-gas because they found a leak which they charged me R100 for investigating it. I then decided to take the car to Halfway Toyota Ottery as I bought it from them and is sill under warranty. I was assited by Winston at the branch who booked the car in and told me to bring the invoice I got from Toyota MacCathy N1 City. He wanted to check if they charged me for the investigation of the leak. They investigated the leak and I was charged R402 for this investigation which I do not understand because I was already at Toyota MacCathy N1 City as the car is still under warranty. I have had many issues with this branch from my extended service with innovative and this branch. Please I repeat do not purchase a car at this branch. It is a risk