UNWANTED DATA BALANCE CUT

MY NAME IS MOHAMMED SALIM FROM GREATER NOIDA UTTAR PRADESH.AT THE DATE OF 11/04/2016, I HAVE RECHARGE 109 RUPEES FOR 1 GB 2G DATA PLAN WHICH IS VALID FOR 28 DAYS.BUT AT THE TIME THEY WERE PROVIDED ONLY 400 MB OF DATA,AND WHEN I COMPLAIN TO THEM FOR REMAINING DATA,THEY WHERE SAYS THAT YOUR RECHARGE OFFER IS FOR 400 MB DATA ONLY.AND WHEN I COMPLAIN AGAIN THEY SAYS THAT YOU ARE USES YOUR 1GB DATA TOTALLY,SO NO ANY DATA REMAINS FOR YOU.
MY AIRTEL COMPLAIN NO.IS :CBNRD30423955289