Actually not every single rep's ordering system will know. The warehouse is located in Toronto. The call centers are around Canada, this means the warehouse system could be delayed to each call center. This has happened many times to me & a few others. Its simply something that many companies have issues with. The warehouse at times does not update the system with the proper amount of phones they have.
The rep put it threw & it got accepted. The warehouse then looks at the order sheet & sees what phone you need, they get the phone, if its out of stock, they will add " Out Of Stock" on your sheet & on the warehouse list.
They can not reserve one. The only ones that can reserve are Current customers with Rogers.