Unfortunately, the session is no longer available if you didn't receive an email confirmation after selecting a time slot.
Sometimes, multiple time slots are listed, even when other contributors have already reserved all available sessions. This happens because the availability screen represents the customer's availability rather than the number of sessions still available to claim.
To remove the test from your dashboard, just click Decline interview.
TIP: You can always check your dashboard to see if you're scheduled for an upcoming Live Conversation. Right after you schedule your test, a Session confirmed notification should appear. You can also look for the banner at the top of your test feed, which should include details about the time and date of your Live Conversation.