VERY BAD SERVICE with FNB Connect

I have two connect packages with FNB that I took out for my wife and son. WHY do they not have connectivity when there is load shedding. When I took out the FNB connect packages, it was explained that FNB connect works off other networks (VODACOM & MTN). So WHY do they have problems with no connectivity, when I have connectivity using VODACOM when there is load shedding???? It is pointless trying to call them as they are no help at all.