It only takes a few minutes: this is how you can get the transferred money back. Since 2009, according to the EU directive on banking transactions, financial institutions are no longer obliged to compare the name of the payee with the customer ID.
You have eight months to complain about a direct debit that has been incorrectly debited. If there is no direct debit authorization, the deadline is extended to 13 months. For the so-called chargeback procedure, you must fill out a form issued by the bank.