I keep being sent to the billing page every time I try to update my applications. Then it tells me my billing information is invalid every time i want to change it. i also can't make payment or even download and update my apps. help me please.
iPhone 4S, iOS 9.3.5
Changing/removing payment info : Change or remove your Apple ID payment information in the iTunes Store - Apple Support
For a card to have a chance of being accepted it needs to be registered to the same name and address (including format and spacing etc) that you have on your iTunes account, and have been issued by a bank in the country where you are (and therefore the country which is on your iTunes account). And credit cards are more likely to work than debit cards (not all debit cards seem to still be accepted by iTunes).
Changing/removing payment info : Change or remove your Apple ID payment information in the iTunes Store - Apple Support
For a card to have a chance of being accepted it needs to be registered to the same name and address (including format and spacing etc) that you have on your iTunes account, and have been issued by a bank in the country where you are (and therefore the country which is on your iTunes account). And credit cards are more likely to work than debit cards (not all debit cards seem to still be accepted by iTunes).
how to change my billing info
