Discovery Bank - Bad banking practice

A deposit was made from Discovery Bank to my personal Nedbank account on the 6th April. POP sent. The money has still not reflected into my account. The staff at Discovery Bank are unhelpful and inefficient. They are not concerned in the least. The account holder has even followed up just to be brushed off. Discovery is holding onto the money and earning interest. I am not the only person effected by them holding onto payments. I find this poor banking practice.