Refund Failure

Nedbank debited my account in error on the 21st of April. I've logged a refund request and supp**** all required documents by the 26th of April but I still haven't been refunded. Every time I follow up I'm told to wait until the next Friday, now I'm told to wait until 20 May!! You're very quick to collect your money but when it's time to pay back you drag your feet!! You're too big a bank to be this pathetic, an entire calendar month to process one payment?? Seriously, get your act together