In Autotune, can you go to the Facebook App area and hit the "Refresh" button? That will re-check the subscription status and should show the correct expiration date. All the Autotune features should work just fine already, it's just that we cache your current expiration date and it likely just hasn't been updated since your new subscription.
I hope that helps, but if not, or you run into any other issues, just let us know.
Thanks,
Alex