Bad Service! Trying for 4 months to cancel!

We've followed all the steps and procedures to cancel end of January and even paid on the final account as requested.<br> For 3 months after we are still getting invoices for a cancelled service & every its queried. Trying to get them to email back to confirm the cancellation has proved futile. On calling them we were told that two lines remain active, even though the account was closed. Apparently closing the account and ending the service excluded these two lines and we were not notified of this upon cancellation. Now they say we need to cancel in writing, even though initially they did request a simple email and acted on it as cancellation. So we repeated the same email, this time on a letterhead and emailed back to CS Retention. We received acknowledgement that the email was received, but not a return email to confirm the cancellation. Now, again we received an account for May, when our notice was for 27 February 2015. We will not pay a single cent further, as a matter of principal. <br> WE ARE APPAULED AT THE BAD LEVEL OF SERVICE BY NEOTEL. <br> All assurances given telephonically to resolve the matter means nothing when we continue to get no email feedback and still receiving invoice