Afraid getting the phone soon is pot luck at the moment, just keep checking everywhere daily.
As for the high risk factor, the quickest and easiest way to help resolve that is to get a credit card, try Vanquis I think they're called, something like that. And use it every month, just for small purchases and most importantly of all, pay it all off every month, every penny. Don't buy anything on it that you don't actually have the money in hand for, so you're only temporarily delaying the payment.
If you pay it all every month, your credit score increases faster than with pretty much anything else. But for the love of god, I can't emphasise this enough, if you're going to do it only buy what you could actually pay for there and then.
You really, really don't want to get into actual credit card debt, seriously that's crucial.
If it seems like I'm overstating the don't get into debt with it bit, good, it needs to be overstated it's important. For one if you get into debt with it, it will have a negative effect on your credit score rather than a positive one. And you'll be paying stupid amounts of interest.
If you even suspect that you don't have the means or the willpower to control your use of the card, just don't get one. If you're sensible and level headed with it, it's a great way to build your credit score and get out of that high risk status.