You need your PUK (PIN Unlock Key) if you ever block your 4 degit SIM card PIN, but unfortunately, obtaining the 8 degit PUK using the Vodacom's 111 self service is quite tricky as of November 2015 - yes I think it is a system error that they are not aware of. Scroll down to the answer section for steps you are to follow to successfully avail your SIM card's PUK.