Hi Shaun,
The next time that you need air conditioning service or repairs, book an independent mobile specialist. They will do a far more comprehensive job than any of the Fast Fit boys and you can ask questions and observe the process yourself. It will be more expensive because the specialists are not hoping to sell you tyres, exhausts or shock absorbers.
In the long term they are far better value for money because you get the job done properly with no nasty surprises.
Simon