What service? To chase you away?

I recently paid the full balance on my YDE account, or so I thought. There was R78 left as a balance on my YDE account to settle it. Thus I paid much more than the required payment. For the last 2 weeks I have been unindated with calls from your collections department for this R78, but why??? I paid so much more than my installment but collections is calling me? You for real? I paid the R80 2 days ago, stop calling me and close this account!