I don't know but have seen some unusual things many times using Airtel
Like in my office my colleague has Airtel Postpaid while I am having Airtel Prepaid and his internet is always flying, even giving speeds like 15 to 20 Mbps while mine just struggles to even load a webpage and same thing I have noticed in my flat also with my 2 roomates postpaid number, are they providing better bandwidths to postpaid users, is there any way to do this?
And not just me, I have seen other Prepaid users also face same thing.