Airtel - Postpaid — Bill even after cancellation of SIM card

Sir,
I the above mentioned Mrs. Meena R. Murthy had given a communication on 16.10.2008 for cancellation of my mobile Sim No.[protected] and the same had been approved alongwith the confirmation that the amount to my credit would be received by me in short notice of 45 days. But once again I have received a bill for the same number which I have already surrendered.So please look into the matter and clear the pending bill immediately.