I received a free spin email 21 hours ago and when I just now tried to use it, it said the free spin had expired...
Are you sure that you haven't claimed that free spin?
The "This free spin has has expired..." message is displayed in two cases.
1. You click on the banner more than 48 hours after you receive the email.
2. You have already claimed the free spin.
Click on "Multiply BTC" at top of the page and scroll down to see your roll history.
You should see the WOF you played recently.