Agents, (Yatra, , makemytrip, TripAdvisor), Airlines indigo, spicejet. Once you use their services, they keep on sending sms to mobile and frequent emails troubling customers.
I don’t know why they are irritating like that.
Indigo and spicejet selling the seats while web checking, i am wonderstruck to know there are no free seats. Airports authority takes bribe from them and keep quiet i think