Tata Nano — the lower body of the car has rusted badly

Address:

New Delhi, Delhi, 110087

I own a nano dl 4cal 4622 and to my surprise i have found the under layer of the car has very badly rusted to the extent it has to be completely changed eventhough i have driven the car only 2500 km in 5 years. What to do? The workshop is asking for 25 to 30 thousand and a few parts are not even availableaftersales of tata nano is pathetic. Workshops keep closing.
They are asking me to dispose off the car as nothing much can be done about it.
Do you think it's feasible to dispose off the car after 5 years after spending so much hard earned money. Please help and advise me