Airtel — do not need post paid

Address:

Bangalore, Karnataka

I have not requested for post paid sim. I was using idea sim and got ported to airtel thru an executive. I have requested for prepaid sim but the executive cheated me and given post paid sim.
The sim got activated yesterday now i want to convert the sim from prepaid to postpaid airtel otherwise i'm ready to throw the sim outside because i do not want postpaid.
Please send an email to me stating i can convert it so that i will change in airtel store.
Loosing respect on airtel.
Please take action on executive, his phone number: [protected]