Actually received an email now from them.
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Hello Lautzen,
Welcome to your free 48-hour trial of Spotify Premium.
Sure, 48 hours is enough time to fall in love with Spotify Premium. But just
when you’re getting used to ad-free listening on all your favourite devices,
your trial will be over. We can’t do that to you!
Just click below anytime (in the next 14 days), follow the instructions, and
we’ll gladly add another 30 days to your free trial.
http://www.spotify.com/freetrial30/
Happy listening!
The Spotify Team
Go to
https://www.spotify.com/account/profile/ to control the emails you
receive from us.
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Question solved