I think that's very BAD on their part, cheap or costly noone has right to misbehave with the customers.
Probably those guyz were frustrated not by you but by their own lives, less/untimely wages, no vacation for years, living away from family etc must have made their life unpleasant which resulted in such harsh idiotic behavior.
In my opinion you need to post your experience at all possible forums, restaurant review sites etc to let them feel the heat.
bytheway there is nothing Indian in that restaurant and for sure this is not the Indian hospitality. They are noway 'star' of India or any thing like that. In my own experience, they are one cheap road side food stall, a money minting shop and don't even make authentic Indian cuisine.