My step-dad banks with Investec, and I don't like them. His card gets declined for just about any online purchase, and you need to phone Investec and tell them that it's not fraud. Their online banking is rubbish compared to the mainstream banks too.
Bs! Maybe tell your dad to stay clear of the porn sites.

I've been with Investec for years without any issues. There service is far better than any other bank's - and I've been with Absa, Fnb and Nedbank.
Their online banking been better than any of the above-mentioned banks - I still use Absa regularly enough and I much prefer Investec. Their telephone banking is in a class of its own and once you have a relationship with your personal banker - things like loans, home loans and vehicle finance can pretty much be arranged telephonically. If there is paperwork involved, they'll come to you.
And I've never had anything declined on my credit card! A mate of mine went overseas and when he bought his ticket, it was flagged. They called him to confirm when he was going over to know that he would be transacting overseas, and even offered to drop off his forex and travel insurance documents.
Oh, and my best experience with them - 4 years ago, we had our first born. On the Friday afternoon, a bloody Absa ATM swallowed my card. I called Investec in a panic, as I needed to pick-up my family from the hospital the next day. They managed to get me a new card on a Saturday in less than 24 hours and sent a driver with R5000 in cash from my account, in case I had some expenses at the hospital and the courier didn't make it in time. That's service!