Account blocked

I have sim contract with them nd debit date last day of the month so last month it happened that the block my account due to unpaid amount after they sent me a billing and I paid that money I always communicate with them calling their customer care making sure that my account it’s up to date I paid and they opened my lines so my problem is that I’ve been getting messages saying I owe R750 how coz I paid the amount required and they open my line why would they open my lines if I owe them they deducted the amounts of R457 without my concern and I paid the remaining at usave now been getting messages some say 350 some say 750 and I inquired about that they said I must I gnore those messages the system has been not updated to settle my account ok so now they gave me my monthly data nd i expected the debit yesterday but still they did not nd I wanna know because I’m worried they will block my account I need a clarification I’m so confused and angry