Constant sms and threats not appreciated due to failures on telkoms part

Last month's payment did not go through. I immediately called and asked that the DO be resubmitted. I was told that I have to go into the store to pay but I will be double debited next month. I keep getting reminders and threatening messages for about R120 outstanding. It's ********* . I've been a client for a DECADE and never missed a payment.