Rejected my R10 note and said it's too old

I'm very disappointed with the service I received from Fruitstop Silverton. I went there to purchase Spinach and mushrooms, when I got to the cashier to pay she rejected the R10 note I had and said "it's too old and the machine won't take it". She even went further and called someone she said was her manager and after the manager left she said she won't be able to assist. I would rate it a zero but unfortunately there's no option for that. Seems like the shop only accommodates people with cards.