Disconnecting Nayatel Broadband Connection

I want to disconnect my Nayatel broadband connection and have called up Nayatel broadband about a month ago about cancelling the connection but till now nothing has been done. I don't want to be paying for a service which I am not using and with the company still providing the service they will expect me to pay for it even if I am not using it. What can I do in order to make sure that the Nayatel broadband connection gets cancelled.

Call up Nayatel customer service again, and tell them you want to disconnect your connection and also ask for a email address and put the disconnection request in writing, mentioning that you made a phone call, the date of the phone call and who you spoke to.
A simple phone call to customer service will do. I would suggest you do this a month in advance to your disconnection and then call up again nearer the time to make sure the connection will be disconnected, also make sure that all bills are paid so that you don't have any outstanding dues to pay later on.