Edcon vs RCS financial services

I have an Edgars account and purchased using the 6 month interest free option, however the book has been taken over by the RCS company and suddenly I’m being charged interest on the purchase made prior to them taking over the account.

I have called the RCS call centre for assistance and went to the Edgars store at Canal Walk and Tygervalley but no one is able to advise on this interest charges.

Surely I shouldn’t be charged interest on purchases made before the take over? My agreement option with the purchases made was 6 months, no interest

Who is able to advise or provide feedback? Edcon or RCS?

Very frustrated customer