Disappointed, no help from staff, no statements, payments are ghosted

So Its just 3 months being a customer of nwj.. I opened a 6 months interest free account and the opening balance was just R667. I paid my account in August, September and October, I decided to send an sms just to see what my balance would be like and I know iv paid a total of R450.. Instead of the balance being R217, it shows R467. I would really like to know what R250 was charged to me for especially if my account is interest free. I also tried calling numerous times to speak with an agent in the accounts dept unfortunately didn't get through and the rep in store told me they cant help. I also receive no statements to even check exactly what's going on. I trusted this group but this is really making me change my mind.