Poor service

I went into the dealer 2019 December to configure the car I was hoping to buy, come delivery time I was told the car I had configured would not be coming as a certain part for it was unavailable. I was then informed of a similar car with just a few configurations missing to it. I was unhappy but accepted this negotiation as I was expecting a new car. I collected the car from the dealer on the 26th of March 2020. 2 months into the use of this Brand new car a defect started to show. The screen which shows vital driving information such as my feul levels, speed, tyre pressure, etc randomly went blank. A week or two after I noticed this defect I informed my person if contact at the branch, and they advised I get the car booked in to diagnose the issue, this was on the 28th of May 2020. The car was booked in for the 10th of June and I took it in on that same date. An issue that was “going to be sorted” in just that day ended up taking two days and I was left stranded without a courtesy car to get around. The car was “apparently fine on the 12th of June and no plan was made for me to get the car, I had to collect it myself. All this us such an inconvenience on my part. On the 25th of June the same issue reoccurred, I again informed the dealer with pictures as proof on the 27th of June as I saw this would be a persisting issue. I have informed the dealer that I cannot take back the car as I do not feel safe using it. This was a brand new car at the time of purchase so I will not settle. I have sent a formal email to the deer mentioning i want the car replaced or my money back and the manager at the branch has not even bothered to contact me fo atleast calm me down or explain what attention my issue is getting. Today, being the 1st of July I was called because the manager wants to again leave stranded and without a car. My installment as well as insurance premium went of yesterday(30 June 2020) and Mercedes Umhlanga expects me to not be mobile. Is this the treatment every customer gets or is this just happening to me? Do I look that stupid that I don’t even deserve simple feedback but just for the dealer to have things go their way? May I please be advised by the dealer as to how exactly I am expected to pay full price for a brand new defected car and still be fine with it, like how? I honestly and very furious and disappointed with all of this.