Negligence

Opened a credit card in January and the payment is via debit order. The money has been going out of my account from my account without no fail. In June my credit score dropped from a 661 due to African Bank, that I'm in arrears. I went to Maponya Mall branch and no one could explain the reason for the arrears and they called the call center and I was advised that the issue will be sorted. The issue was sorted and my credit score increased. Now in August again I'm in arrears yet the debit order went off and they even sent a message to thank me for the payment. This has a negative impact on my credit score and I don't even know the reasons for this. I need answers an compensation for their negligence.