Most unprofessional service ever!

I was eligable for an upgrade on the 21st September 2017 and had browsed through the Mtn trader to make my choice days amd had communicated my decision to my branch in advance so I could make sure my upgrade would be available at the store by the 21st latest. The staff there said they didnt have stock and were waiting for it to arrive and that it was likely to arrive on the 22nd its been a week of frequent visits to the mtn branch and they have not recieved the stock also the deal os about to expire and my upgrade could not be processed online because after a certain step it would say the website is undergoing maintenance. I feel like Mtn is buying time so that that this deal expires and its very unprofessional to tell the staff that you will be sending stock amd inconveniencing clients when theres no service delivery.