Airtel — Airtel is cheating the customers

I had done booster pack combo booster 119, which I got an SMS from airtel service, saying it will have the validity of for 180 days and I refered the samething on the www.airtel.in. But after recharging it I got only 90 days. for that I called to to the customer care booked a complaint in which I got the response that it was a limited period offer. But while calling the customer care and getting response for the complaint, web information says 180 days. My advise don't believe the SMS and information on www.airtel.in.

They are cheating by giving the wrong informations.