I wasn't able to connect more than once with my 3Gb Telkom "Advanced" account, which as per the the TelkomInternet website, is meant to allow 2 concurrent connections.
I don't use the account every day, so I only noticed this problem yesterday. After calling 10215 last night, the guy I spoke to sorted it out within two minutes.
It's a pity not all problems are solved this quickly. It annoys me that you have to phone and request this, when it's something they advertise and you pay for.