Cannot install or update apps

I've recently bought apps and songs from the App Store and iTunes Store and two did not go through and went as 'pending payments'. Ever since then I have not been able to download apps or updates to my iPhone or Mac. Each time I try to, it comes up with a pop-up saying 'There was a problem with your billing info'

MacBook Air

iPhone SE

If anyone could help with this, that would be great.