Tata Motors - Fraudulent service by SELECT Cars Chandanagar of TATA motors

We recently purchased TATA Nexon XM model car during month of October **** from one of it's dealers at SELECT Cars located at Chandanagar and unfortunate incident occurred while driving the car in city, where a small dent formed near the bumper of car due to collision of the car with another vehicle.
The incident occurred somewhere in middle of November ****, for the resolution of which we contacted the SELECT car dealer at Chandanagar, who in turn promised us to get the servicing of the car from TATA authorized service centre located at Sanathnagar.
Going by the first impression of his genuine claims that car would be serviced at authorized service centre , we trusted his claims.
But towards our shock,when the car got delivered after servicing of the dent we observed some greyish colour marks on some parts of the car imbedded in the white colour of the car.
On bringing it to the notice of the car dealer about the new issue, he further promised us to get the problem rectified.
After the passage of * week time from the date of dispathch of the car for servicing, when we visited the authorized service centre at sanathnagar to get our car delivered, towards out shock we found the car placed at some nearby local car service centre in sanathhnagar, where it was getting serviced which was nowhere connected to the authorized service centre at sanathnagar. The service centre was maintained in a very unprofessional manner which we could gauge from the first impression of its appearance.
When asked to explain the reasons for non complaince of their claims of getting the car servicing from authorized service center, the officials of SELECT cars at Chandanagar put up a blank face with no proper reasons to back up, which reflected their fruad intentions to get the car parts changed to old ones like tyres,batteries etc, which we came to know as most prevalant fruad practice by automobile service centers.
After the occurance of this incident, it left bitter taste and disgusting memory on part of the service done by TATA Motors representatives.
We want assurance from team of TATA Motors that such incidents will not occur in future because when trust of the customers is broken nothing can replace it. I understand that TATA Motors realise the above fact in this consumer oriented age.