National Highways Authority Of India [NHAI] — I am complaining about toll charges

I am travelling from chennai and i am on my way to madurai and so far i have crossed 7 toll plaza. I am writing this note on behalf of my father. He is working for indian army for past 38 years. I have seen a display board always before entering the toll and which says toll fees are exempted for army personnel but i had paid for almost 3 tolls out of seven.. From this i have learnt there is no respect for persons who works for country.. Such bad experience.