My money not welcome at Dischem

I went to Dischem on 22 September 2015 to buy a few items, when I was paying at the till with a R200 note, the cashier said the money was stained and she had to confirm with her supervisor. When the cashier came back, she said the supervisor said she must not take the money. The supervisor also asked if I was a black or a white customer!!! What does that have to do with anything? I asked what was the reason for the money not to be taken as they had confimed it was genuine on the UV light and they said it was stained and their machine would not take it. I asked the manager where they have put notices to customers that they do not take certain money and there was no answer, instead I was met with a bad attitude and was told I was not allowed to buy, I must go and ask for change somewhere. A manager by the name of Vincent refused and said he will not take my money, therefore I was not able to buy. How is it my problem as a customer that the money will not go through their machine? What information has been shared by Dischem to educate customers that they do not take certain money? What a bad attitude, I will never buy from Dischem again.