Hyundai - Service of the car

I express my dissatisfaction with the inadequate and unsatisfactory service that I received from hyundai service centers. On March **th, ****, I dropped my Hyundai XCENT SX *.* CRDI (Diesel) car, with ***** KM driven, to KPR AUTO AGENCY PVT LTD, located at Bannimantap, Mandi Mohalla M-* & M-*/*, C.V Road Mysore, for inspection and maintenance.
Unfortunately, upon receiving the car back from the service center on March **th, I noticed several major problems such as engine vibration, black smoke from the exhaust, increased engine noise, and the engine turning off when shifting to first and reverse gears. These issues were not present before the service.
I immediately contacted the service center representative on March **th, ****, when I faced significant problems while driving the car and requested for the footage of the service done from day * of my notice of my car problem after receiving the car. However, I was disappointed with the response I received as Hyundai showed no concern and refused to take ownership of the issues. now they are not providing the CCTV footage also. How come a car serviced and immediately engine got seized this shows lack of diagnosis, carelessness and lack of ownership and poor service.