havent been able to update apps. now it asks for a billing info but wont allow me to put in my billing information

What happens when you try to add your billing information? Error message(s)?

Apple ID - Payment methods that you can use with your Apple ID

Apple ID payment information - If your payment method is declined, or you have a billing issue with a previous purchase in the iTunes Store

If necessary, contact iTunes Support. Scroll to the bottom of the page in the 2nd link. Follow through the screens to get a chat or telephone option.

iTunes Support

iTunes Support – world wide