Best Recharge Offer for Airtel Users

Freecharge is giving Cashback on Airtel user too
Max 300 rs Cashback with BILLFREE Promo ode
And then Use DTH75 for 10 % cashback then use TEN (non airel)
Just done 310 (got 150 cashback) then 15 cashback then 2 cashback
These R old codes but they R working with airtel too or I am late ??
https://www.freecha...in
I just done