Still no delivery of order after 17 working days

I ordered an airtime on the Black Friday online on the 22 November 2018. Delivery was supposed to happen by 10 working days. I have called the call centre about 4 times and they say it is out for delivery. My delivery address has been updated by the call centre and yet still no delivery has been made. I have sent numerous emails with no response except one saying it has been escalated. Still nothing. I cannot get through to the national call centre for the branch that is supposed to dispatch. I stay on hold for more than 5 minutes at a time. The last call the agent promised the manager would escalate and come back to me. Still nothing. What do I do? It is now 17 working days since I placed the order.