BSNL — Not shifting the connection and issuing bill against old address where no one is residing now

Address:

North 24 Parganas, West Bengal

Sir/ Madam, I have shifted to this address on 01/03/2013:
Sumit Kumar Biswas, C/O: Sri Prabir Kumar Biswas (Near Darogabari), Vidya Sagar Road (Arabindapallli), Noapara, P.O.: Barasat, 24 Parganas (North), Kolkata- 700124, West Bengal, India.
My Previous address was (before shifting):
Sumit Kumar Biswas, Teghoria Main Road, Block: B2 (1st Floor), Sujata Apertment, Teghoria, Kolkata: 700157 (previously 700059), West Bengal, India.
At that time, I have applied to shift my landline (landline Number: +[protected] in proper format maintaining all norms. I have applied to the proper Authority of Bharat Sanchar Nigam Limited, Barasat Exchange informing everything to the authority of Bharat Sanchar Nigam Limited, Nager Bazar Exchange.
The order to disconnect the line was issued on 10th April by the proper authority of Bharat Sanchar Nigam Limited, Nager Bazar Exchange. But till now it is not executed and hence the remaining works to shift the land-line is pending.
But unfortunately, in-spite of the fault from the side of the Bharat Sanchar Nigam Limited, they are issuing the telephone bills against my previous land-line number regularly which is really shocking as no one is not residing at my previous address and the instruments including the receiver and phone has been carried to my new address by me at the time of shifting.The was done as it was instructed verbally by the authority of Bharat Sanchar Nigam Limited, Nager Bazar Exchange.I am attaching the scanned photocopies of bill for the month of March and May together-with the scanned photocopies of payment receipts for the month of March and April.
Now I am totally unwilling to pay for the bill for the month of May. Please look in to the matter to settle it and to help me to get the shifted connection of the land-line in my above mentioned new address.
With deep regards, Sumit Kumar Biswas