Denial of boarding for local flight

I had booked aa flight with Mango Airline to Durban, when checking I could board the flight because I didnt have my son's birth certificate. I dont understand why the new unabridged visa requirements apply to local fights. They asked for my son's clinic card (which I didnt have), but I produced the medical which reflects him as my dependent. <br> The staft at Mango were very rude. They dont understand the definition of customer service. <br> Government owned airline, clearly dont seem to understand the need for income in the tourism sector. The sad thing, Mango (subsidiary of SAA) is not profitable. <br> All I want is my refund and never to fly on Mango again.