Shocked as employee insults customer unprovoked

I just witnessed one of your employees Brenda hurling insults at a customer because the customer had pointed out that they got his order wrong. The sad thing is the customer was travelling with two children and they had to listen to Brenda’s vile language. After this i couldnt even order any food as i was disgusted by your employee Brenda and her Manager. All this happened whilst the manager was looking and she just stood there whilst Brenda kept provoking the customer. Brebda was in the wrong for getting the order wrong could she not have just fixed it? Was there a need to get violent? KFC is this the customer service that you teach your employees? This is very sad and disappointing. Im sure there will be no repurcussions but i hope there will be enough people who read this review and will stay away form KFC M2 Denver at the shell garage in Johannesburg