Confused

I took out a contract and was advised that delivery will take place within 3 to 7 days as I was approved. I called in on Monday to check my status of my delivery, I was then advised that the application is not yet complete but they do have stock. I called in on Wednesday as I had received two consecutive sms's with a reference number. I was then told they do not have stock. I called in again today and was advised that the device in question is now being discontinued so they will no longer receive any stock. I do not understand how one day you have stock and the next 2 days you don't. Surely when doing a contract and it has been approved stock should be set a side? That is what I would think but it does not happen that way. I now have no options when it comes to devices as the only stock Cell C has is Huawei.