Manager who refuses to speak to clients

My girlfriend and myself went to McDonalds at 10:45 (the closing time of McDonalds is 11PM). Part of the reason for going there was because she needed the bathroom and we wanted to grab something to eat on the way home. The Security guard however would not allow us into the establishment disregarding the fact that she needed the bathroom AND it was before closing time. and despite repeated requests to speak to the manager, they simply refused to come to the door to speak to us. Not only is this the worst McDonalds I've in regards to food quality, but also in customer service. I will never be going to McDonalds Milnerton again. This is the last straw after many unsatisfactory times there.