When I logged in today all my playlists were gone. I had several that I could get back when looking at my friends who were following. But the majority of my playlists are nowhere to be found. I have put a lot of effort when creating them and are very sad about this.
Quickest thing to do is to get in touch with the customer services team directly using the online contact form and they should be able to get those restored for you.
If you get an automated email reply back directing you to the community or help pages, you need to reply directly to that email (even if its from no-reply) and one of the customer services agents will get back to you as soon as possible.