Unacceptable waiting period for device

On the 18th of March I walked into the Mtn Branch in Sandton city shopping centre, <br> I added a data bundle with the Mobile WiFi router to my existing contract, I was told that they do not have stock in the store but that the device will be sourced and will be available for collection by that Saturday, I then decided to go in on the next Monday to find out if they have received the device and was told that they are still busy sourcing it, I have since visited the store twice to find out if the device has arrived, Last week Monday I was promised the device would be available by Wednesday, Today is Monday again and I have still not received any feedback from them.<br> I have been waiting for almost 3 weeks now and this is totally unacceptable, if this continues ill be forced to cancel the add on and take my business elsewhere