Account payment

So I made a payment via EFT instant payment of R500 on the 10th April thought Mr price App. Iv realised that after a couple of days my payment is still reflecting so I called call center and then I was advised to send proof which I did send on the 17th but till now no one rep**** to my mail till today. I'm very disappointed in Mr price and cannot allow this to happen as my account is gonna incure interest for non payment which is not my fault. This is bad service