Expensive aircon repair

I had problems with the aircon of my car. I took the car to ibayiautoaircon have it checked out. They told me that the accumulator had to be replaced.

They gave me a quote with the accumulator, labour and regas. Told them to order it. A month later I still haven't heard from them, so I send them a message. The woman told me that she had forgot about it but she will order the part now. They told me that I could bring the car that Thursday( I live 80km away).

So I asked my wife to take the car there only for them to tell her that the part is not yet there and asked if we could bring the car the next day.

After calling back and forth we agreed to come that Monday and that they would discount me on the regas of the aircon because we had to drive another 160km in total.

My wife got there, they did the job and when she was on her way back I asked how much it was. They charged me for the full amount.

This is not acceptable as they told me to bring the car, they knew I lived far away and did not have the part. They failed to let me know about it so I mean, that is a very expensive trip now.. that is 320km in total for their mistake.