Charging interest on an interest-free account!!

For the past couple of months now I have been trying to get Edgars to rectify the mistakes on my account. They keep on charging me interest even though I have a 6 month interest free account.

They keep on telling me that its me, that I dont select the correct account type when I order online, or that I dont advise the cashier when I purchase in store... but the issue is that there is no option to select an account type when buying online, and when I do buy in-store, I specifically tell the cashiers "6 months interest free", which they then confirm!!

Between Edgars and RCS they are wilfully *****ing from me... and I guess from other loyal account holders as well.

If this mess is ever sorted out, I will never support them again. They have a complete disregard for client service - they actually dont care about the customer.