get a prepaid debit card from like your local grocery store or 7-11 and put like $10 in it, then use that. some can be refilled - you only pay as much as you want to put on the card + $0.50 to $1 or so for the card itself.
I don't have any money
...cmon dude, not even $5? there's no other way to get a card that I can think of...
have you tried convincing your mom to let you use it? make sure she knows it's not to buy anythingotherwise maybe call their customer support (definitely what you should've started with) and ask
i'm not good with phone calls