Being charged interest on fully paid up credit card

<p>Good day</p> <p> </p> <p>I noticed that I have been charged interest on my credit card even though it gets fully paid off every month. I phoned ********** 000 to check why this is. I spoke to Nkululeko Mhlanga and after holding on for 5 minutes got cut off. Then i received an email to rate the service. I prefer not to rate the service via that email. </p> <p> </p> <p>Then I phoned again and spoke to someone else and after 5 minutes got cut off again.</p> <p> </p> <p>Can you please let me know what's going on?</p> <p> </p> <p>Thank you</p>