Mahindra And Mahindra — Service not done properly & loose the internal part

Address:

M/S-Jai Kumar Arun Kumar Sector 2, Partapur, Meerut, Uttar Pradesh 250103

Dear Sir,
As dated 20-Mar-2023 service done by Authorize dealer of Mahindra And Mahindra M/S-Jai Kumar Arun Kumar Partapur Meerut-U.P.
But wrongly done the service & loose the internal part of Bolero car and now Bolero Near Karnal loss the speed & stop.
So please help for fast solution. Currently service branch not accepting the mistake.
And this is repeated mistakes.

Thank you