Spotify premium Not working on iPhone or iPad showing as free subscription

[Stuartcant]

I have tried to use Spotify on my iPhone today and it won't allow me to play offline, even though I've had premium for many months. It says my subscription type is free and even when I try to select a song it doesn't allow me. When I click shuffle play that is the only time a song will play. My iPad has the exact same issue. I logged onto my account on the website and it said my account was premium. Adverts are now appearing when I play music which is not what I have paid for.

Can someone please help? This seems a very strange issue after never encountering any issues.