Indigo Airlines — Reg. Chennai Airport Indigo Airlines Manager- Arjun

I travelled from USA to chennai and I booked ticket from Chennai to Trivandrum through Indigo Airlines and I was told that there is a charge for additional luggage and also indigo airlines has international travelers luggage concision.
I reached the airport 2 hours earlier and went for check in they told i need to pay Rs.7600.00 for additional luggage. They don't have flight from USA so they cannot give concision for my luggage.
I spoke with the Manager Mr.Arjun to cancel our tickets since I am not aware that USA Flights cannot be given Luggage concision.
He treated us like beggars his attitude and his reply was so arrogant and nobody can tolerate it. I paid my luggage cahrge and travelled but hear after I won't recommend anyone or travel in this airlines.