MyTVS — Car Battery not being replaced under Warranty/ Irresponsive Service

Address:

B-18, 1st Main Road, Ambattur Industrial estate, Ambattur, Chennai, Tamil Nadu 600058

We took our car for Complete service in September 2021. During the process, they mentioned that Battery's performance is poor and they will change it and install a new battery. Bill was given for installation for new battery. When we enquired about the warranty for Battery, they promised that it would be covered under the Bill and submitting the bill will be sufficient for Replacement of battery in case of any issues within 2 years of warranty period.
It's been just 3 months and car didn't start at all. When we checked, we found that Battery is drained completely and it's not working. We informed MyTVS and submitted the battery to them on December 1, 2021. Till now, battery is not replaced and the service Executive is answering us irresponsibly.
Please do the needful.