The wrong-account problem is more common than people expect because Spotify supports several sign-in methods. The support page explicitly tells users to try the login routes they may have used originally, including email, phone number, Apple, or Google. That is sensible because Premium can look as though it has vanished when the truth is simply that you are looking at the free account instead of the paid one.
Payment status is the next serious checkpoint. Spotify says a payment marked as pending on your bank statement might not have completed successfully. In that situation the pending hold can expire and the funds can return if the payment fails. That is an important distinction because it means not every suspicious banking entry is proof that Spotify took a valid Premium payment and then withheld the service.
Shared plans have their own logic. Spotify's Premium not working article says Family or Duo members may lose access if the manager removed them or if verification could not be completed. That means a Family or Duo issue is not always a playback problem at all; sometimes it is an account-status problem that has to be fixed inside the plan structure.
If none of those checks solves it, look at who is actually handling the payment. Spotify says partner-billed subscriptions are managed by the partner for payment matters, and it points users back to the account page to find the provider contact link under Payment. In other words, the cleanest fix is to identify whether this is an account-login problem, a shared-plan problem, or a billing problem, and only then contact the right support route.
Source: Official: Premium not working