Bad service at Woolworths Northgate

I had a very bad experience with Woolworths Northgate just an 30 minutes ago I over paid by mistake by R100 at the till, and I noticed few steps way from the till,the management,then asked the cashier to take the money and go and cross check him self, I then asked why is he the cashier taking the money alone with out someone, in his company, I was then told I must trust them , after the cross checking was done I was told ,the cashier had only R4 extra on his till, I then asked to check the footage , because there is a camera not far from the till that I was , the manager then **** to me and said the camera is not facing the area that I was ,,and even if I want to check the footage I must open a case and get a court order, all can say is that we all make mistakes,of which I over paid by mistake, in my case the Woolworths shop manager should have checked the footage by them self to verify ,what I have raised