Essar Petrol Pump — Unethical behaviour

I went to essar petrol today on 14/6/21 pump located in parvat patia named pari petroleum, i filled 2000 diesel and went to fill nitrogen, after filling nitrogen attendent says its chargebale, i had no objection to pay but i said why are no charges written he say talk to manger, manage says its nor written free means its chargable, i said u must put charges board regarding chargea so people know what are charges and its free or not as many other essar pump offer free nitrogen instead of agreeing on putting charges board he say s i[censored] r not able to pay charges you are not compentable or driving or owing car..and he wipp no put charges boad according to him if its not wriiten free it means its chargable...its such a unethical and rude behaviour from owner as if he is owing me by filling my car..very disappointed with such a unethical and rude behaviour company must take action for such customer service