Useless Vodacom call center

I have been a loyal paying customer to Vodacom for more than 10 years , issues started when I wanted to terminate my contrat with them in feb , I have made calls to them a million time their call centre has been *******, dishonest and a waste , I have called so many time to cancel till today Vodacom has been debiting my money , with no help I even have reference call of the calls done , what made me mad was when their call center agent hanged up a call with so much disrespect and attitude, I have reversed this month’s payment , they have the disrespect to tell me my account is overdue which mess up my credit because of so called professional call centres agent that doesn’t do their job, I demand my refund for all debit orders taken and the explanation as to why is it hard to cancel this