Who trains their staff???

Extremely disappointed in Nedbank. I have been struggling for the past few months having them update my new residential address on my bank statements. Surely this can not be such a difficult task??? Every time I speak to someone they tell me its been updated and will reflect on new statement but few weeks down the line it still shows old address. This is extremely stressful as I don't have any accounts and I need my bank statement as Proof of Address