Withdrawal button
If you bought tickets for an event in Argentina, you can undo the purchase within 10 calendar days of receiving the tickets or the receipt, as long as you do it at least 24 hours before the show and no ticket was used (Ley 24.240, art. 34). You do not need an account: only your order number and the email you bought with.
If it applies, the order is cancelled at once and the money goes back the same way you paid. Either way you get a request code right away and by email.
The number of your order is in the confirmation email and on your order page (it starts with TK-).