How do I persuade my parents to let me have a BlackBerry Curve?

Around christmas time before your parents bought you the Samsung phone you say your were going to buy the other one so why cant you buy the other one now? You say the Samsung isn't as good as you thought, do you mean that you want the Blackberry so you can use the internet? Do you realise how much it would cost you per month to use the internet on the mobile? In the UK you are taking around �60 per month on pay as you go because the cheapest package of around �20 per month only gives you 1gb which works out at 2.5 hours per month which you know would not be enough for you to use? Who would be paying it per month? Maybe your parents cant afford the cost or think you can use the one you have, there is no way you can change their minds and they have the final say. Good Luck.