I'm getting this for my folks, but I'm sure I can change the DNS on their router, it wasn't one of those free ones that they restrict, I'll do a test at their place first with my Netflix and Unotelly accounts before I make the order though.
If your dad's router has dodgy MWeb firmware, you should be able to flash it to the proper unrestricted firmware from the manufacturer, and get the latest firmware update in the deal. I have a Billion router at home that used to be locked to IS, but I flashed it, and now it works on any ISP. You should be able to get the latest firmware and instructions off the manufacturer's website.
Note: There is a risk that if you eg lose power in the middle of the update or something, there's a chance you might brick it.
PS: Any idea where I could get one of those plug adapters? I think most of the travel adapters you can get here will be the wrong way round
PPS: Think I just found what I need
http://www.capeunionmart.co.za/go-adaptor-plug-visitor