billed for an account that was cancelled and confirmed cancellation

I had an adsl account with neotel, and cancelled it when i was moving out of the premises i was staying. I sent email for cancellation and even received confirmation and also received call from engineers to come remove outside unit. They never pitched and i moved out left the unit there. they billed me for all months i was out of country and i even then arranged out of my way to talk to body coorporate for that complex so they go in and remove the unit. Now they still charged me for services for 6 months, i have asked for a data usage report for this to no avail. Neotel has become a vulture preying on those who cannot voice their arguements, i am taking this up with consumer protection SA as someone needs to shine a spotlight on them