Verification can mean that a payment method you have entered is no longer valid. Remember, the people responding on this support site are only other users like yourself. If you have already started a discussion with Apple and have take all steps you can to enter verified payment there's nothing we can do, sorry.
- Are you using a valid payment method? --> Payment methods that you can use in the iTunes Store, App Store, and iBooks Store - https://support.apple.com/HT202631 (Discussions on this forum mention some countries do not accept debit cards, and even if they do some items cannot be purchased with debit cards.)
- If your payment method is declined, or you have a billing issue with a previous purchase in the iTunes Store - https://support.apple.com/HT203005 - various reasons why payment method is declined.
- If this abruptly started happening try removing and re-entering your payment information - Change or remove your Apple ID payment information - https://support.apple.com/HT201266
- Do the name, address (all spelling, letter case and punctuation), and card numbers exactly match those you have entered? You didn't mis-type anything?
- You entered the 3 digit security code for the card? Correctly?
- The country for the bank and your address are the same as the iTunes Store country you are using?
- See the end of the document linked above for special measures that may be necessary for some cards, plus about contacting your financial institution to make sure your records match.