Exploitment

Took my car in to do a roadworthy certificate they told me I must redo the lower armbushes in order for the car to pass the roadworthiness and was also given a specific time to bring it back I sorted out the armbushes but could not take the car back in the time period eventually I came back from my course and took the car back in for a retest knowing fully well that I would have to pay the full amount again which I did, they tested the car again and then they told me that they could not clear my car because they can't see the engine number ,I asked them how did they find the engine number the first time a came to them they told me that they used a special camera to find it then I told them to use the same camera again they said it's broken then I suggested that they pull the info from their data base then they refused they opted to dismantle some of my engine I told them that they will b liable if anything breaks, they then said I must bring my own equipment to check for the engine number. It feels like they want to exploit me cos they didn't find anything wrong that will make the vehicle not worthy ,they want me to keep coming back so they can exploit I also asked them if they treat all their customers this way they told me m wasting my time and dd nt answer me