Birch Communications Billed for services after disconnection date Macon Ga Georgia

I have been a Birch customer since 2008.  I just moved my office and I needed to switch to the phone company of my landlord.  The new provider notified Birch of the line loss and the service was disconnected on 7/11.  On 7/19 I receive a bill for services from 7/15-8/14.  I call them and they said I owed this bill because "I" had not personally contacted them to disconnect the line.  See the hypocracy--they would disconnect my line without personal contact but would not stop billing me for services they are no longer providing until I had personally contacted them.  By the way--I was paying $79 a month for services for which  I am now paying $29!  Seems I have been taken advantage of a very long time.