I need to reset my billing stuff I canceled my card and it won't let me delete it on my iPad and I have 15 dollars I can't use on that Apple ID

If you are trying to change your credit card info and you have cancelled the one card, then you need to add the new card, then make it the default card, and then you can delete the other one. If you have any additional issues, then contact iTunes support for assistance. http://www.apple.com/emea/support/itunes/contact.html

You will need to replace the current card before deleting:

Change or remove your payment information from your iTunes Store account (Apple ID) - Apple Support

And why are you unable to use $15 on your Apple ID? You only need ever have one Apple ID. If the email change, change the email attached to the apple id.