Best call centre experience ever

I've been banking with Investec Private Bank for about 18 years now. I do 99% of my business through their online banking interface, which is powerful and full-featured. However occasionally I need to interact with them through their call centre. Considering my experience with a whole lot of other companies' call centres, the Investec PB call centre experience is fantastic. Their call centre agents are ALWAYS knowledgeable, friendly, speak clearly and understandably, and effective. Honestly I've yet to have anything less than a 5* experience with them. Other call centres could well learn from this one - kudos!