Think about how dumb they are being. Picture they allowed data to rollover (Like ADSL Services), they would make a killing on Fixed-LTE now that ADSL is at its last. This would boom especially in neighbour woods that do not have fibre.
I just ordered my Cell C Fixed-LTE 100GB Service as well through Axxess this month as my ADSL service was pathetic.
I was wondering the exact same thing when I saw my pro-rata data did not roll over.