Account Still Being Debited after Cancellation

After requesting a cancellation in beginning March, I was not informed of a 30-day notice period and was billed again at the end of the month. I called the contact centre for an explanation and was advised that the notice period is the result of the deduction, but this month was billed again! After receiving reassurance that it will be resolved! Unacceptable that one must chase you guys for answers and you cannot handle queries is a timeous fashion. Been on the phone for nearly an hour now, as no one can point me in the direction of who to escalate the matter to. Not happy with this level of service delivery at all!