Customer care, waiting 30 min before phone is answered

On Sat 2 Dec I received a SMS from Nedbank warning me about a low balance on my current account. In a panic I went into the branch in Nelspruit, I was told to use the phone inside the bank to contact customer care. I waited 29 min without anybody answering. The help desk lady then tried to get hold of customer care as well, again I had to wait another 28 minutes before someone answered. Surely Nedbank should expect high call volumes over month end and should make sure there are enough people to attend to queries. Waiting 30 minutes for a call to be answered is not acceptable, especially a big Co like Nedbank.