failure to service as promised

fnb business has continued debiting my account for a speedpoint service that was cancelled months ago, they've now closed the business account after i repeatedly advised them that they were debiting incorrectly. I have since emailed my complaint and to date I've received no form of communication from the bank, even though i was advised that this would be resolved within 48 hours as two departments had to communicate with one another. Is this how you treat your clients? Bank account nr. ********** 629