Air Asia — Unfair policy as regards extra seat

Full fare being charged for extra seat and booking shows 7kg cabin+15 kg checked in baggage but at airport they don’t allow.After booking they send an e mail that extra seat won’t be allowed baggage allowance.Talked to Customercare now and they say that it is their policy from the very beginning.All airlines allow concession in fare(indigo allows75% fare charge with 20kg checked in baggage plus cabin baggage)Senior citizens are even given more privileges but here they are denying any baggage at all.Why 100% fare is being charged then?
Booking says 7kg+15kg for extra seat them how can they deny at the airport?

They are telling that this policy for extra seat is from the very beginning.The policy is not proper since when anyone carries extra baggage he/she is charged @500/- per kg atleast by each airline which amounts to Rs.21000 for 22kg.

Strict action needs to be taken against such unethical policies m.I call it cheating.

PNR U4DIRJ (4 seats)