Hi @Cally_McIntyre, thanks for reaching out and sorry for the trouble here!
By default, all current team members will receive an email notification for requests to join the team and any member can click through to approve, but you can limit these email notifications to a specific set of members. If all members of the team received the notification, someone else could have approved the new request and that’s why you cannot cancel it.
If the issue persists and you were the only team member notified of this request, I recommend you contacting our support team and send them a screenshot of the email you received. Unfortunately I don’t have the tools in the forum to confirm the number of seats in your team or the status of the request.
Let me know if you have further questions, Cally!