Mr Price-Bad Service

I ordered online a pair of paints for my son's graduation which took place on the 9th Dec (yesterday). I placed the order on the 1st Dec and paid R34.99 for an express store delivery to be delivered at the store in 2-3 business (because I looked everywhere for those pants but with no luck), when I checked online the status of the delivery kept showing "Shipped" meaning it has not yet been delivered to the store. I called them on Friday the 8th and spoke to a guy named Joshua who advised that he checked with the courier and they advised that my order was delaying and it will only be delivered on Monday the 11th, I told him that they need to do something because I paid that delivery charge because I wanted my order to be delivered on time as I needed it for Saturday. So, I asked to speak to his manager and he placed me on hold for too long then came back saying him and the manager are discussing the matter to see how they can assist me and they will call me back. I waited for their call, till today they haven't called.