Burger King Rustenburg

Good day, hope you are good.

Just want to lay a complaint against Burger King in Rustenburg. I went to go and buy Nutella fushion and wanted to pay with cash. They said to me I'm not allowed to pay with this R20 as it has a cut. I told them I also got the money like that from somewhere so what am I supposed to do they refused to accept the money so I left with my money.

Is this real customer care what if this is my last money and I don't have other money to buy with. I'm very disappointed in them.