Bad service

Car service city honeydue ohw no the worst service ever. I think what hurts the most is the fact that they messing with a very valuable asset, that i use to put bread on the table for my family. I took my car for a major service at honeydew car service city (you can imagine how much i paid for a major service). They claimed they performed a mojor inspection on my car and quoated me for aircon gas refill as it is not included in the major service. Okay fine i give them a go ahead to refill the gas and pay an additional fee ontop of the major service fee to be paid. Okay fine, i collect my vehicle trusting that these people did a great job "value for my money". 2 days down the line, the aircon is no longer working, like how is this possible. I called them and enquired as to what happened because i paid for this service (goods). They ask me to bring in the car so they can check and advised it will take 2 days. Ohw no, now i cant work, no work no money no food on the table for my family. Well, they take in the car and do whatever they claim they did, only to find myself having to pay more money to them, as they claimed they diagnosed the car again. But how l, like how is this fair or making sense as this was their fault for now doing a good job and their machine failing to identify all the faults on the car. And mind you the gas was already detected and refilled. So what am i paying for, they say well i can come collect the car and will pay this fee only when Im opting to fix the leak. On my arrival at the car service city center, they threaten me that they wont release my car until i pay this fee. What nonsense is this, this is so *********** , a ****, day light *******. How do you rob people like this though. Totally unfair. Do not take your car there for service please, because i obviously paid for services not performed.