Paying a premium delivery charge but receiving a ****py service!

I placed two online orders in the last week Both I opted for the 1-3 day delivery

The first order was place on 21st and supposed to be deliver on the 27th (today) Since I planned to be on leave, I called the support number first thing Monday morning, before they even started processing the order, and asked to change the address from my office to my home address. A few hours into the 1-3 working days time span. (This was also around the time I placed the second order, to be delivered no later than Monday 31st at the office) I requested that the operator please call me back to confirm all is in order. Tuesday morning, I still have not received any feedback and called again. Another operator confirmed the address has been communicated to the warehouse. Yesterday 26th, (public holiday) I noted that the 2nd order status was "Shipped" and the 1st order status changed to "Complete", and I followed up on the matter first thing this morning since nothing has been delivered. Operator Eugene told me he would follow up with the courier and give me a call back before 12:00. 12:00 came and went and no call received. In the meantime, I tracked the order on the courier website ON THE DOT Track and Trace. 10:37 both orders was stamped as "Business Closed"... I assume the address was not changed on the first order, still shipped to the office, and having spoken to reception this morning I know the office is definitely not closed. So I called again. This time I spoke to Zinhle, who was unable to tell me what is going on with either order. Promised to call me back... Having not been called back either time this promise has been made I asked to speak to the manager... Dalene Randel was on a call and will call me back? I explained that reply was an issue for me, how long should I be waiting for this call? An hour? Two? Next week? She is unable to give me an estimated time, as soon as she is available... Paying a premium delivery charge but receiving a ****py service!