Home-Connect at it again

Almost 10 years later and the service I get from this provider continues to shock me. There is no communications inter departmentally. A bill for more than R3000 which should not be on my account is being charged, reversed, charged, debited from my bank account (when the only amount I have agreed to be debited is monthly service fee of around R750) then I reversed the ******* debit. Paid monthly service fees. Daily threats via WhatsApp and email about this "outstanding" amount and now service disconnected. Third major complaint in 18 months. Can't change service providers because of their contract stipulations. Now they are going to call me non stop instead of fixing their mistake