Not happy

I was promised a refund or credit on my account more than a month ago. Called the call centre numerous times and messages were sent and still no one has gotten back to me. With another debit going off tomorrow I called this morning and still no feedback. I was promised a credit of R720 for being overcharged R40 per month for 18 months. Well now it's 20 months so I should be refunded R800. I also get charged penalties for debits not going through . Can someone pls contact me as this is really not on. Thanks