Refused my money

I placed an order at their drive thru.. The line was quite long...when I got to the window to pay they refused my R200 note because the corner was torned off. I said: It was the only money on me, and I don't understand why they can't take it since the bank gave it to me. The lady just said sorry and I asked what I should do now because I am hungry and I want my food. She just said that she doesn't know. So I had to leave the que feeling quite embarrassed and without food. They didn't even offer to keep it for me. Bad service and just unbeleivable thet they refused my money.