Mtn data simcard

05 November 2025 i open an contract for sim card data which was R329 for R100GB,even on my contract its there however when i received an invoice for December it was R630,12 when i call mtn they said its a pro rata data which i wasn't told about it in the first place,the lady didn't disclose such information to me and my contract can prove that because i only see R329 .January i also received an invoice but they didn't debited the money when i called the next day my price went up because of erraus of which i wasn't told that they are no longer debating i need to pay in cash, i received nothing about that communication. And my contract is terminated with R705 fees of which i need to pay,how did we get to R705 ?