Poor customer service and lack of respect from Nissan grobelstal

The customer service at Nissan grobelstal service department is very poor and it looks like no1 care.its been a month and a week since I took my Taxi there for diagnose which they did and said the car needed computer box which we paid, that was on the 01feb 2021 todate there car is not yet fixed. What is disappointing is how unprofessional and lack of integrity the dealership lacks..I would personally never to recommend any1 to buy Nissan brand if that's how they handle their clients for service