EDGARS AND RCS CANT SORT OUT SIMPLE THINGS ANY MORE

I am Edgars Customer for an extremely long time and only had 1 issue last year, but since RCS started handling accounts the system is a mess, i have a 6month interest account but im being charged interest at 17.5% every month for the pass 3 months, when i called the 1st month they said oh ya we see its an interest free account we will put in a query or you, i received an sms to say adjusted according to discussion, 2nd month still interest when i called they said some ****ches will be sorted out, this month still nothing sorted, IS RCS TRYING TO FORCE OLD LOYAL CUSTOMERS TO STOP BUYING FROM EDGARS AND ANY COMPANY THAT IT IS AFFILIATED TO IT?????????????????????????? IF THEY CANT SORT OUT SIMPLE THINGS IN 3 MONTHS HOW CAN THEY BE ABLE TO RUN BUSINESS FINANCE??????????????????????????????? IM SURE IM NOT THE ONLY CUSTOMER THAT HAS THIS PROBLEM