Paypal won't let me purchase on Xbox?

[Zonda]

Basically I've been trying to purchase gold on xbox with my paypal linked to just my basic bank account I'm 15 years old if that has any effect?.... and when ever I go to buy it i get this error "We could not get authorisation for this. Try a different or new way to pay. If you have more questions, please ask your bank" My paypal is verfied and the bank account is confirmed...? any help would be greatly appriceated  I also tried matching my billing addresses on xbox and paypal but that should'nt be the problem?

[snowshoe]

You must be age 18 or older to have a PayPal Account ... unless you have a Student Account.