Fnb - no smooth sailing

I’ve reached out via the website to explore the possibility to reduce my overdraft interest rate. I’ve received a mail with a number to phone. Sibongile answered the phone and said I need to phone a different department (after I phoned the number as per the email). I queried this, I was either disconnected or cut off. No one bothered to phone me back. I’m still nowhere closer to a resolution. Please confirm steps/numbers to apply for reviewed interest rate