Consumer Redressal

hi, i havent used the data plan for two months for which aircel chennai has sent me a bill for unused data after august of about 1200INR for month after august 2014 . i have no idea how can i pay for the plan i havent used , when approached to disconnect the connection on august the customer executive asked to bring my mom whose proof i used to open the account but executive dint ask to bring my mom whose proof i used to open a connection last year why cant you disconnect ? i requested to disconnect on august which they dint take into account . aircel is asking me to pay the amount .