phone order cancelled without notification

I called into mtn call centre and spoke to a sales consultant in beginning of January and mad a order for Sony Xperia Z3 compact as there was 3 black in stock/ I done all that was asked and was told phone would be delivered in a week from the call. called a week after I ordered and was told my order was cancelled as the process took to long, I wasn't given any notification my order was cancelled when I was waiting for delivery. during the call of telling me its cancelled I get told a sales consultant would call me for my order again as they only have 1 left in stock, no call from sales. so I call again yesterday and I get told there is no stock of the phone that I ordered in the beginning of January when there was stock. I don't think this is fair or customer satisfaction at all as I order something and it gets cancelled without letting me know then call again and get told they will call me when there is stock. I have been to all the stores and called but yet no phone stock, but yet mtn advertises the phone in pamphlets and on tv. poor service from a provider I have been with for years.