First, check the spam or junk folders. There is a chance the email with the ticket was automatically filtered by your email service.
If the ticket is not there, there could have been a mistake in spelling the email address when you made the booking. In this case you can identify the tickets seller on your bank statement. Usually, the name of the company that received payment is indicated next to the charged amount. Contact the seller to see if your email contains the correct spelling, and if so, have the document resent.
We are working to add to our application, the ability to automatically track the name of online travel agencies. This should help in cases like these, or other inadvertent errors.
You can always contact us at email@example.com so we assist you to find the seller.