I think that his point is that it was not free.
Assume that the pre-discount flight price was R1000 (to make things easy)
Then he got the 30% upfront discount to R700.
He then got cash back of 70% of the R700 (which is R490).
So the flight still cost R210.
Unless I am missing something.
This is exactly what I mean! The cashback earned now shows at 100%, yet we have 4 weeks left for our trip and keep meeting goals, we now cant earn anymore cash back. So in essence we paid 30%, which isnt bad, just confirming that its NOT a free flight