When my credit card expired I got the following e-mail (I live in Sweden, not sure if the message looks the same world wide)
We've tried a number of times but have been unable to renew your Spotify subscription.
We will try to process this payment again over the next couple of days. Should the payment not be cleared soon, you'll start to hear ads and, if you had a Premium subscription, you'll lose access to Spotify on your mobile phone.
To prevent this, please contact your bank to find out why the transaction was refused, or set up a new payment method on your subscription page: https://www.spotify.com/account/subscription/
If you are currently paying with PayPal, please verify that you have a valid credit, debit or bank card connected to your PayPal account, as you can’t pay for your Spotify subscription with only your PayPal balance. http://www.paypal.com
The Spotify Team
Should you experience further problems, please don't hesitate to contact Spotify Customer Service http://www.spotify.com/about/contact/contact-spotify-support/?payment
You can also find help from other Spotify users in the Spotify Support Forum http://community.spotify.com/
In my oppinion it could have been a bit more informative (since spotify know for a fact that the credit card is expired) however it was really easy to find how to update the credit card details on the /account/subscription pages.
The good thing is that there were no disruption in the service and no playlists were lost. So I guess as long as spotify have your current e-mail address you can keep rocking without worries.
My concern is does it get reported to the credit bureaus as being late? My pmt always deducts in the 30th or 1st of the month, I just found out my debit card expired because my service was disrupted. I never received an email. I tried to call the # from my bank transaction you guys list but it just directs you to the website. I finally made a payment but the answer to my question is not on the website at all. It's been about 13 days from when my payment normally goes through, is tha enough to report to the credit bureaus as being late??? I'm freaking out!!! No notification at all and not one live rep to talk to! Someone please let me know!