Payment was declined

Apple continuously declines my payment. My visa credit card is still working, and there is some money in it. There is no way that Apple could say that payment declination. I can’t download new apps, because my iPhone SE (old) keeps saying “payment declined.” I can’t add new card, because it is the same with the old one. I have updated the old one, it still doesn’t work. Please, help me. Thanks beforehand.