Yep, I had the exact same problem! The reason you don't have an order number and nothing appears on MYO2 is because they use a different kind of system, they have a preorder system so they know if you've paid and the system will have allocated you a phone most likely too, but because you haven't actually upgraded yet (your new tariff hasn't been activated - this happens when you collect the phone) it doesn't show up on MYO2. CS told me that this was normal procedure and that you simply need to take the receipt in and a form of photo ID to collect the phone. It should also say on your phone when you can collect it (mine says 'Your phone will be ready for pick up on Launch Day (Friday 19th Septemeber)').
