Bill charged wrongly

Dear Sir,
I had opted vodafone mobile service for my no. 9930755905.
During this time I had subscribed GPRS service pack of Rs.98 per month.
After few month I requested to discontinue the same but the customer service executive called me for retension same time I agreed to continue the service.
But after that I came to know that when I received the bill the service has been discontinued and internet chagres charged w.r.t. per KB.
I mailed to vodafone for the same and asked for discontinued the servive for this number. After that I paid the valid charges but not paid wrongly applied charges. But now they are not deducted the same and charging that late chages to me.
I had written many mail to the vodafone but it is not rectified yet and even sending mail for discontinued the mobile service it is not disconnected yet.