I bought too many tickets because of a problem during the purchase. Can I get a refund?

No. Regardless of the circumstances (connection issues, payment errors, duplicate purchases, etc.), tickets cannot be returned, exchanged, or refunded. The association cannot be held responsible for any technical issues or malfunctions experienced by users during the purchase process.

However, you may transfer or resell your tickets to another person without any formalities. 
(See above, “Is it possible to resell a ticket? How?”)