Woolies Store card used over the set maximum limit

I have been woolies customer for years. Have a store card that I barely used. Had a copy made for my kids which are living my ex wife. To my surprise the credit limit was maxed and over used. How does woolies allow a store card to be used over and above the credit limit?! What is the point of having a credit limit if can be overused?

I contacted their call center and told me to go to the store where this happened. Now I am supposed to fly to Johannesburg (Northgate) for woolies to explain how this happened? This is ridiculous!!