Angry and dissaponted by Edgars

i've been an Edgars account holder since 2003,frm those years i've never had a problems with them until last year November 2022 i went to Edgars maponya mall to enquire about my instament going higher every month, only to be told about a 6 month plan that was in my account with i know nothing about,i was on a 12 month plan from the beginning of my account with them,they said i must first pay that month's instalment with was over R800 which i failed to do and the following month so my account accumulated arears for those 3month.i payed the whole arears monthend march and they promised to convert that 6 month plan to my orginal plan which is a24 month because they nolonger have 12 month plan,and we agreed on that until today they not fullfilling thier promise they now telling me to pay up the whole amount in my account before they can change that 6 month plan which i didn't sign for.