I got this as a response when I emailed them then: Įmail back with screenshots of at least one of those receipts, and you should get access back.
If you did that already, it might just be because it's a weekend that you haven't gotten a response yet, so if you only emailed yesterday or today, you might not get a response until tomorrow (or potentially Tuesday, since it's MLK Day tomorrow in the US, though with Spotify based out of Sweden, who knows). Just do what it says: contact Mention your email that should be on the account, and the email address it was wrongfully changed to (I suspect, by a spammer, because the same thing happened to me back in October).