No twins currently flying in Maun.
Regardless of how many hours you come with, it's an absolute minimum of one year before you're considered for van progression with any of the operators that fly them.
Progression is mostly down to luck with regards to your place in the seniority list. Two guys can be hired a week apart in the same company, but if there's little movement at the top, they can end up over 6 months apart in terms of progression to turbine. You win some, you lose some.
If you're only in it for the turbine time, maybe try looking somewhere else.