Prize tag amount refused

I wanted to buy a dress that cost R109.90 - clearly stated on the price tag. The manager refused to give it to me at that price. He said it was an typing error and should have been R1099.00. He went and changed the price after the incident. (I have photos of both price tags.) Not only did he not care about what the law says, but did he treat me badly in front of other people and didn't even apologize for their mistake.

YDE, Cresta Mall, Johannesburg, Gauteng