Over billing

I'm on Compact Plus, which costs R519.00, On the 11 Jan 20 I made a payment of R664. which is more than the premium amount and i supposed the reconnection fee is R50 so i was charged an extra R95 . I want to make payment today I check how much I should pay and it say im owing R949.32 im tryin to figure out how did yall come up to that amount you guys are just Robbiing us for your useless service i called ur call center to get assistance on this but your call center agent Nompumelelo told me you are offline at the moment I must call after 2hours instead of her taking my details and call me back how pathetic