is axis bank banning axis airtel cc or something for doing other people bill payment ?

I don't think so. Those Airtel axis card holders who haven't already please dm with your offer, need a lot of prepaid recharges.

well maybe the price of telecom hike made them use it for themselves more because that way they get 25% themselves instead of 15% or 10% after discount giving on trading  

Similarly, I used to give rupay DC offer on trading too, but these days i stopped Rupay DC offer since i only have 2 rupay DC and i use it efficiently by timing my bills and paying my 5 or 6 prepaid airtel connection personally by timing it

this way i get Rs. 100 all for myself than Rs. 60 or Rs. 50 after trading discount