Useless cellphone service provider

MTNs services are absolutely **********. Nevermind the service itself but even the customer service is completely useless. Trying to make a payment and cancel my contract but 3 days been calling and asking for invoice and banking details and still waiting. They won't resume my services without payment but yet they also refuse to send an invoice so I can make payment? Sent emails, have been in store and made phone calls but absolutely noone can seem to help me? What a joke?