phone not delivered as promised

I received a call from a call center affiliated with telkom mobile saying that Iam due for an uupgrade and that I would receive the phone in 4 working days, it has6 days now.the office number I was given has no response at the other end.***.I have been trying to find out where the phone is as well as trying to change the delivery address. I am really concerned as I am not going to pay for goods I have not received.