I do not know the names of any specific chain stores or anything in Europe, but here's the best advice I can give you.
Go to a super-market. The most general store that you can, the bigger the better. I think in the UK there's something called an Aldi that fits the bill, but I'm getting the feeling you're not from the UK. Anyway, go to the general store. Ask them if they have pre-paid debit cards. I do not know the specific branding or organization they would be under in Europe. Basically all that should happen is you give them 15 dollars/Euros/whatever, and they give you a card with 15 units of currency on it. You enter that information in on the payment thingie, no need for paypal. There is no risk, the worst that could POSSIBLY (it won't) happen is that the evil starfarer devs take that 10-15 dollars and you don't receive anything. That argument is for if you need your parents to buy the pre-paid card by the way.
