Unprofessional/********* behaviour

I deeply regret having visited the local McDonalds today. I ordered a happymeal and 2 mcfizz. The total according to the board was 70.00. Having been told that i must pay 73.50 i enquired from the lady 4times why. She was terribly confused and responded "you must pay that" with no further explanation. A person(zakhele) intervened extremely rudely and said "you must pay" 3 times without further explanation.I then asked for the manager (nhlanhla) who seemed to repeat what the other 2 said . On asking why and with a confused look on his face tried to explain that the prices changed today but the board was not removed or replaced. Without an apology or further explanation they all walked away leaving me embarassed by their behavior which happened during the lunch rush. This is not a matter of the R3.50 but the unprofessional and rude behavior. Sies.