What is the Point of Pre-Ordering?

So i pre Ordered the new Samsung Galaxy S6 Flat the day that pre-orders opened online (Cell C Website). I called in a week later to find out if Cell C is aware of my pre order and the gentleman said not to worry as he will personally also pre order the phone for me. <br> <br> I called in on the 10th of April to upgrade my contract and was assured that i can expect delivery on 13 April 2015. <br> <br> I called for an update and was told that there is no stock available for me where they specifically told me that they have stick on the day i upgraded. <br> <br> What is the point of offering a Pre-Order service but when it is crunch time there is no stock. No one can tell when stock will be received. <br> <br> POOR service and not managing customers expectations. I have been a Cell C customer for almost a decade. <br> <br> I am leaving the country on holiday in a weeks time. Should i rather go to Vodacom?