One thing relates to the De Witt project (and not Complex as everybody wants to mix up), I think your underground mining figure per annum is wrong, it should be
As per BFS Total Underground ROM Production is 110.0 Mt
So if you divide it by 30 years - approximately 3.6Mtpa
And the open cut mining adds another 1.2Mtpa for years 3 to 5which gives a grand total of 4.8Mtpa for those years.