Different standards

Had the worts service ever at a kulula. we flew from george airport checked in with no problem, flying back from johannesburg 2 days later Wow what an experience we went to the check in counter, suddonly we didnt have the right documentation witch is untrue. received emails ect and flew the first time with the same documentation then the check in clark phones her supervisor and start having a conversation in her own language without us understanding after another story both of them became rude and unhelpfull. How is it possible that the information and service differ from airport to airport it is the same company