Mr P Online cannot keep their promises

I placed an online order on the 14th. I made sure before continuing with my order that delivery date will be the 18th and paid for store express delivery. It is afterall a long weekend. The order was shipped on the 15th. My brother went to Mr Price Tokai mall to check if my parcel has arrived and the lady said they only get deliveries on a Monday, Wednesday and Friday. I then called the online store department and spoke to Mishandre. She said she will contact the store and will get back to me. This was at 15h00. I waited till 16h00 and phoned again, this time I spoke to Asanda, who was unwilling to help me, as Mishandre was handling the query. I then said (yes sarcastically) that you guys are closing at 17h00 as per the email that I received, so how is Mishandre going to phone me back. Asanda then informed me that they in fact close at 17h30. The order stated that delivery will be before 17h00. 17h00 my brother went to the store again, as I received no feedback from Mr Online's staff. And he went home empty handed. 17h30 came and went, no call. It is now the 19/04/2019 and no call. I guess they couldnt even phone the couriers. This is not the 1st time this is happening. Why have an option for Store Express and you cannot deliver on your promises? Why have a call centre when they cannot even track where the order is at that point? And Mr P online should not even tell me that the email says estimated, cause it said 2-3 days. This will be my last time that I opt for this option. I guess the order will be delivered on Wednesday the 24th.