Vistara — Rude, Unethical, inhuman, fatal, unapologetic, exploiter flight staff

I had witnessed below issue at London to Delhi airport:
1. The tickets which i purchased didn't say that we need to wear mask and i totally forgot that mask is required in flight.
2. When i checked in my luggage no one told me i need mask but it was mentioned on my boarding pass however i didnt read my boarding pass.
3. When i was entering the gate there is an old man ( he also checked in my luggage and was on board in the flight however he refused to share his name) he said i have to go back and get mask. I told him how will i go back now i will miss my flight he said i dont know ask for mask from other passengers and beg for mask if they dont give you we will not let you in.
4.. i said this is ridiculous, why do youwant me to do that ( I could see that Vistara already had masks lying on table foe passengers who dont have mask and a lady was giving those to passengers who didnt have mask already) luckily a lady behind me gave me her mask.
5. Then another vistara employee who was extremely rude and calling out boading announcement started yelling at me 'ma'am that person is right you have to get your mask go to boots n buy we dont care. I told him this is clearly harassment then he said go and read meaning of harassment. None of your employees r wearing name badge and mask for that matter on ground .
I have paid INR 40K for this flight n mask is hardly worth 10rs. Vistara upsets you and bully you at the time of boarding.
Seat number: 37G
Flight number UK 18
Date: 3rd June
Place of incident: Heathrow airport