Credit card Increase Process

Been with Nedbank for almost 8 years now. Called the service line to increase my credit card limit. After almost an hour, the consultant told me that my application was declined but could give me no reason for this, as I met all the necessary criteria. Consultant was a bit clueless, and just told me that they would contact me within 4-5 working days, why so long, I have no idea. Will definitely be moving to a more efficient bank.