Mahindra going out of their way to hide info for the customer

Very badly rusted Mahindra xuv *** model with 44 000km on the clock.. Under warranty Mahindra send it to the Dent shop because they said they have the right to choose who fix it. After at Their choice of Dent shop their was still 3 doors rusting thrue the panels that is 3 lyers of steel at the boot is rusting all around. The bonnet was already replaced because of rust last moth but new bonnet got 3 areas of new rust on. I insisted that the car be said to a panel beater that II will know about. They insist that I must bring my car to them and they will take it to the next panel. Beater for a quote. But no repairs will stop this car with its bad substantial defect and the only way I can proof it is a full body and bumper to bumber inspection is done. But mahindra don't want to tell me where they will take my car. Since they know I will probibly call the Dent shop and tell them where to look for all the rust. Mahindra is paying the Dent shop and I will just not let my car be repaired again under only mahindra supervision. Since they did it 2 tipes and alot of rust was just painted over and not even repaired. The cost effective panels can tjuat be replace or repaired. So they were just painted over and the rusted rubber was just but back on a gain. Probibly hoping we will not see it.