Bad attitude and UNFAIR inconsistent service

Used SAFAIR for the first (and last) time, obviously the big draw is that it's cheap for us four to fly to CT to visit family. The flight to Capetown from OR Tambo went well, we all got on with just hand luggage to make a fast escape at the end of the flight. When booking in at Cape Town international we were told that the very same bag that we had flown to CT with was now deemed not to be hand luggage and we must check the bag in (and pay R250)! The teller smirked all the while! They put the bag in some contraption that is supposed to resemble the overhead lockers and decided it didn't fit, while we know it does as we had it in there on the way to CT! these are standard items! How does it make sense that we flew with the bag to CT as hand luggage but must check the same bag in on the way back? No weight difference? When I asked the teller she imp**** that OR Tambo staff don't follow regulations? While we were fighting about this another person was told to measure their bag and it didn't fit but they didn't need to pay or book it in as we did? Once on the plane we noticed the exact same bag as ours from another traveler in the overhead locker! Very disappointing!