Try to avoid closing the signup process before confirm the email, as it will allow your to edit the email address (in case it was misspelled) or re-send the confirmation email. Please make sure you have used the correct email address, and check your Junk/Spam folders as the emails may end up there sometimes.
If you have closed the tab with the signup process but you are sure you have type in the email correctly, you have another option of correcting this. When you try logging into that account you will receive an error that the email wasn't verified yet and, at the same time, another message with a verification link will be sent to your inbox. Use the link within that email to activate your account.
If none of this solutions is helpful, please contact us and we will help make your account accessible shortly.