App Store and Billing Problems

ok so basically i had a credit card linked to my phone to make purchases on an app a few months ago, and a problem has come up recently where when I try to download an app from the App Store, it tells me to sign in to view my billing information. i ignored it at first and just forgot about downloading another app, but it got annoying so i removed/unlinked the card from my phone thinking that would change something. but it still tells me to sign in to view my billing info. i tried deleting all the billing info too but it just brought it back again. what do i do? help :(