Device delivery and feedback

I took out a contract with MTN (online) was approved and then assured by both the sales guy and customer care that my device would be delivered to me within 3-10 working days. We are now on day 18 and still no device nor feedback on when the device may be delivered. It is extremely frustrating as I have emailed (response is that they were out of stock but would still deliver in the 3-10 days) and phoned customer care but unfortunately all they can do is escalate to the sales department. I just want to know how much longer I have to wait.