Mr. Rohit has given valuable advice. Kindly follow it.
Do you have the copy of the form you filled and signed for issuance of the connection, terms and conditions issued to you and accepted by you, receipt of the advance deposited by you or the last bill showing advance/security amount deposited by you, complaints lodged by you with the complaint numbers, detail of the calls made by you for lodging complaints, copy of the inspection report of the engineer/technician who visited to fix the problems…………
At this juncture it is most unlikely that company shall share these with you. Moreover the record of the calls made to you is being maintained by the company while you may not be keeping any record.
In such situations it is always better to speak the language understood by the company. Visit the local BM of the company along with your near and dear ones and some influential and experienced acquaintances and collect the details as mentioned above from their computers in the office. The staff in the customer dealings would be having it. If you are able to create enough noise in the office you shall be able to obtain it. The local BM/Collection Head/Customer Service head can waive of the penalties, late payments etc.
The only issue is that companies e.g. Airtel don’t give any printouts of the complaints, disconcertion requests easily hence you shall have to build enough pressure on them.
If you are living in a society or have a welfare society or union the office bearers can tell them they shall be denied business. If someone misbehaves, you may record the transactions and then use this as a handle to resolve the situation in your favor.
Customer should always issue instructions/orders to disconnect the connection in writing under acknowledgment mentioning the lapses/deficiencies in service and thus building favorable record.
If you had asked for disconnection quote it and obtain waiver.
If you are willing to pay the amount of actual usage you may succeed by asking to adjust the advance with company and to issue you a printed NOC/NDC and FNF payment receipt with seal and signature of the competent employee of the company.