Are you sure you were logged-in when buying the tickets? If you are not logged in and you try to purchase a ticket, you will be asked to fill in your personal data like name and birth date. If that happened, the tickets are not showing up because they were not bought through that account.
Another thing to check would be if you got the confirmation e-mail. You will get these in any case, if logged in or buying as a guest.
If both of these fail, check in your payment method if the money was actually taken and not given back. If something in the buying process fails, the ticket sale is automatically undone and you will get back the money. However, then you also don’t have a ticket and if you were controlled, that would have been noticed (and you would have been fined).
