Car repaired and next day broke down on the freeway

I left my van in to be re-gassed and it lasted about two months. I returned it to the garage who re-gassed it initially and they inspected the van and reported that the Evaporator and TX Valve needed replacing plus Sundries screws, cable ties, crimps, fuses, sprays, oil, clamps, hose, heat shrink, tape etc! Also rubber o-ring. Cost $1,433.00
They explained in order to do this they had to pull out the complete dash board.
I also had problems with the gears they were very difficult to change and the problem was that the Clutch Master Cylinder needed to be replaced also and bleed clutch.
Apparently both the Evaporator and the clutch Master Cylinder were in the same area under the dashboard.
The cost now went to $2,134.00 and was in the garage from Monday to Thursday.
On Friday morning I was driving the car and as I was driving along the air conditioner failed and about ten kilometers later I was on the freeway and the van came to halt.
I have been driving my van for five years with out any problems and it has never broken down before . Wondering why when it just came came out of this garage that the van broke down.
Anyhow I rang the garage and got them to pick up the van and they eventually got it back to their Garage late Friday afternoon and about 5:00 pm they rang me and said that it appears that there is a problem with the compression and three of the cylinders is working incorrectly? And when they return to work on Tuesday they will investigate further. And let me know?
In the mean time I am concerned that they will charge me for picking up the van and presenting me with another bill for further repairs. Saying that it was not their fault after all they done the repairs and it is likely they will put the blame elsewhere!
The name of the Company is Autospark in Canning Vale Perth WA.
I have done a research on them and they have only one review and this customer said that he left his car into them and they said the same thing and quoted him $1,400.00 he took it elsewhere and was quoted $357.00. And his car has been running well since having the job done. He mentions to be aware of Autospark!
Also Autospark of Canning Vale were fined $10,000.00 and $962.00 for operating costs for operating without a licence.

I would very much appreciate your advice on this.
Yours sincerely,
Noel Nagle