In 2018 I made a reservation with Tesla for a Powerwall by "paying" 500 EUR. After being ignored for months (someone was supposed to contact us regarding the installation), we started asking for the money back. Didn't hear anything. Started sending an email once a year, in 2025 they finally replied asking for bank account details to send back the money.

Cool.

Ask them for the interest too. I would imagine the 2018 to 2025 inflation entitles you to at least another 200 EUR on top of the original sum.

I don't think the original terms of contract volunteered you to act as a lending institution.

I think this may be a purposeful tactic. It’s like raising investor money from people who get no shares for their money. These reservations are just scammy.