Bad and *********** service

I have been battling for almost a month with the accounts dept but an outstanding amounts. I have been paying R175 short from Jan -Jun 2017 and was notified in Jun of the short payment. I was told I owe R875. I paid it and also corrected the monthly payment from July. Now they tell me I owe them R1817 . How is it possible, even sending the proof of payments of all the payments I owe them so much. Even speaking to Lesego at finance she can't explain why the amount is such because I pay every month, even did 2 payments in June to correct it. How can a company have such *********** people who can't add up the amounts correctly. This is so frustrating. My parents medical aid has now been frozen until I pay their outstanding amounts. Even though they are incorrect. They asked me to complement them on Hello Peter. No way can one complement incompetence.