Worst service

The service by MAN Truck and Bus Centre City Deep branch is the worst ever. I need information about the battery that fitted by them and the truck doesn't start at the moment. They asked VIN number and whole lot of other information. They first denied having fitted the battery but' it has MAN sticker on it. The guy later agreed that they fitted the battery and even sent me an invoice. One minute they said the battery is no longer under warrant and they later they change and confirm that the battery is under warranty. After two hours of back-and-forth WhatsApp messages, they asked me to call a call Centre.