Gross negligence

I've been using this online shopping app since, Runway sale. To my surprise, while browsing the online shop I found numerous items for R0. NULL, Zero rand. I add the items to my basket and paid the R60 delivery fee. Order was excepted, and a few day later received another email that confirmed that all was in order and reminded me of the shipping times. I was fine with that. Out of the blue I received a email that my order was canceled, and Genevieve responded that they couldn't source the products. Only a *** would believe that, and with the new reserve times on the carts, that is impossible, and on further inspection, all the items were still available, but at a price. Numerous emails back and forth she forwards their cancelation policy. It states that they can cancel except for "GROSS NEGLIGENCE". ITS BEEN ALMOST A MONTH, I ASKED HER TO DEFINE, GROSS NEGLIGENCE. Either someone is paying with the job, or someone doesn't now their job. Don't cut and paste t&c if you can't defend them.