Vistara - Rude and misbehaving ground staff

Ground staff Mr. Rajendar and Mr. Gurmukh were pretty rude and misbehaving. They do not know how to talk to clients and a woman.
They both don’t know how to resolve a query or how to reply to client when they are in distress.
My baggage was above ** kg and i told them i am ready to pay they denied first by saying no one is allowed to do so, but i told them i am travelling internationally and i have did this many times. Then they told me to separately get another bag, which i agreed and asked where can i buy, Mr. Sandeep was frequently telling me to go and talk to Authorities , which wasn’t the answer he supposed to give . Then I literally raised my voice out loud to remind him what i was asking for and being in customer service level he should have talk better and answer what can resolve my problem. In moreover Mr. Gurmukh was quite a undisciplined and unmannered staff as he shouted to one of the staff from Indigo if what i am saying is correct that indigo allowed me to pay extra money for my extra baggage it was quite humiliating by him with full of laugh in front of entire airport full of people .
In mean while Mr. Sandeep entered into the situation and he apologized me for Mr. Rajendar behavior and help me to resolve my problem and provide me one cartoon box to keep my extra stuff and even he helped me to pack it nicely so no damage will happen.
Entire thing happened today at **th May ****, at Dehradun airport flight no. UK*** from Dun to Delhi.
As first time traveler from Vistara, I am looking forward to receive reply from vistara and i really want a lesson to teach Mr. Rajendar and Mr. Gurmukh and please equip them with good customer service training.
Thanks