Paid my account but not reflecting

I paid my Mr Price account at the correct time when I was supposed via that *120* number. The amount has gone off my account but is not reflecting on Mr Prices side. Call numerous times only to be transfer to this person and that person. NO ONE HAS ACTUALLY HELPED ME! Now my account is charging me interest which is not fair and nor is it my fault that they have "lost" the money.

I would like this situation fixed now! I have proof that I paid but no where to send it to!