Nissan incompetence

I took my bakkie (2012 Nissan NP200 1.5 DCI 80 000Km) for a major service to NTT Nissan in Secunda in January 2018. With a defect on my air-conditioning unit. NTT Nissan is the only company that worked on my vehicle from new. Nissan charged a total of R17 000, of which R4500 was for the air-conditioning unit. The service was completed and they reported that an air-conditioning unit pipe had to be replaced on the air-conditioning unit, which needed to be ordered (2 weeks). 2 weeks later, the part arrived and the vehicle was taken on for repairs. Repairs was done and the vehicle was picked up. The air-conditioning only worked for a few days and was taken back, Nissan said that the pipe was not installed correctly or something to that effect. Nissan had to order the pipe again, which took about a month. Vehicle was taken in again for the repaired, which was done. And 2 days later and the air-conditioning packed up again. At no time did anyone contact me for feedback on this issue, I had to phone myself to find out what was going on. Customer service!!! Nissan said that they are trying to sort out the issue which took a few months and eventually in August (after I called Nissan) the air-conditioning was sorted out and is now working. 2 weeks later, I take my vehicle for the a noise coming from the engine and they tell me that my water pump failed, according to my research, if the fan belt was over tightened, it can cause the bearing the water pump to fail (how long does a water pump on a vehicle with 80 000Km last?). Is this really a defect on the vehicle or shady workmanship, of which I’m paying for? This is really unacceptable. I paid another R5000 for the replacement of the water pump. Now, I also notice that there is a problem with my gears, which is having a problem to select. All this from a fairly new vehicle which only does local runs from home to work, which is 40km a day. I really don’t want to take my vehicle back to NTT Nissan until some from Nissan HQ check my vehicle themselves. I looking for a new vehicle at this point in time and I don’t think that I will go back to NTT Nissan. If no action is taken on this matter, the letter is going to the press to tell people of the terrible service from NTT Nissan.