Poor service

I lodged a complained before regarding my cancellation, they responded on Hello Peter and said the matter was sorted, the arrangement was I will pay my cancellation over 5 months. Yesterday I received SMS stating they will deduct R1 600 plus my monthly subscription so I called and I was told "THEY DONT HAVE IT ON RECORD SO I MUST PAY R1 600 PLUS SUBSCIPTION" because invoice is already issued. If you debit my account I will reverse the debit order. My subscription is paid in advance my should my account be debited for service that I'm not using anymore. If the original arrangement is not in place I will reverse the debit order.