Billing Information Required for App Updates
Officially, you should probably engage Apple's official App Store support to verify your account / get advice how to make things right.


https://support.apple.com/itunes
https://support.apple.com/contact


The former usually has a more direct link to App Store support and you can usually tap links on iOS as well or use the iOS support app which is a free download (but not likely to work if your account is locked)


https://itunes.apple.com/us/app/apple-support/id1130498044?mt=8


Lastly, Twitter and Facebook have official Apple Support presence if you like social media to engage, but unless your situation is covered in a knowledge base, they will steer you to official support if you need personal attention and the FAQ aren't helping you fix your error condition with your account or setup.