Wrong decision buying Nexon (Tata)

I actually followed this car since the time it came in auto expo, was keen to to buy it as soon as it was launched. I bought Nexon Diesel XM model model on December 2017 and since then its been a terrible time that I have faced and still facing.

When I took the delivery from Okhla Tata Treo showroom, immediately after driving it from the showroom car engine started missing, there was no pickup, I called the service people and they sent some person next day to check, he did something from his laptop after connecting it in the car. Then he told me to drive and see, same thing happened again after a day or two lag in pick up no torque at all in the car. Again I raised a complaint, same procedure was followed and nothing happened, then after sometime I went to the workshop, they updated a software and told me to drive it and give a feedback.

Same thing happened after I drove it for 100-200 kms lag in the car with no pick up. Same procedure again the senior technician came at my place and when we went for a test drive, missing and lag happened in front of him, he then called his senior and told him about persistent problem, they told me to leave the car at the service center, which I did, after two days they called me that it is ok now and you can take it, I took it and on my way back same thing happened again.

I called service senior person and told him the same, he told me to leave the car, which I did the next day, it took almost 10 days the car was with them this time. They called me and said that everything is fine now, you drive and give your feedback. I took the delivery from service station and again the same day, same problem repeated.

So the charm of buying the car I wanted to buy for which I waited for such a long time has disheartened me and now I feel I took a wrong decision buying this car. Still my problem is not resolved.