Bad service

I took my Nissan NP200 to DTM Nissan Strand to look at a problem with the clutch shuddering. I asked reception if I could please speak to the workshop manager to explain when the shudder occurs and that it does not do it 100% of the time during normal driving. I was asked to wait in in lounge area which is an all glass area. After a while someone walked past with hand gestures and swinging arms and I was still trying to figure out who this was intended for as surely it could not be for me. The receptionist walked in and confirmed that it was actually for me and that he wants me to meet him at my vehicle. I went out and tried to talk to him and give my explanation which he flatly ignored and insisted on taking me for a drive in my vehicle and explain why it shudders. During the drive I was lectured in looking at the revolutions of my engine when pulling away to prevent the shuddering and was told that it is not the clutch but the engine mountings. When I eventually had the chance to tell him what I wanted to say, which was that the shuddering in heavy slow traffic becomes so bad that it is un drivable. During this lecture I continuously mentioned the fact that it becomes un driveable and I find his reasons unacceptable . At this stage I was getting very irritated as I have been driving for longer than he existed and never heard of a vehicle where you have to only let the clutch out at certain revolutions when pulling away. I then posed the question to him that "are you telling me that this particular model shudders due to the engine mountings and I must accept this". His answer was "yes and if you have a problem with this take it up with Nissan South Africa". Needless to say I lost my cool totally by this time and slammed my door shut when I got out. He then handed my key to the receptionist and told her to give me my key and take my vehicle somewhere else after I told her that I did not come here to be told I cannot drive or for a driving lesson.