Hyundai Motor India — against m. b hyundai gorakhpur

Address:

Gorakhpur, Uttar Pradesh, 273013

My car's engine has been repaired for last 2times in a span of 1 year by m. B hyundai first time with a bill of 46 thousand and second time by a bill of 86 thousand and again having the same problem for which they had repaired. Inspite of accepting their mistakes they are again asking for 40 thousand rupees to repair.
Tell me just one reason why shouldn't i sue them for negligence and recover whole sum of of money we have spent and the mental harrassment that we have suffered.
What the hell these hyundai customer care people are doing if yhey don't have any redressal mechanism or control over their service providers.
Not lessthan 10 mails regarding this issue have been sent from my side to receive nothing in return.
Car no br01-as 1049