Is this letter legitimate and what should I do?

Attached is a letter that my partner received.

Here's what happened: On December 1, 2022, we booked a vacation online for summer 2022. When we booked, we were informed that the key for the property had to be picked up from a completely different location. We then googled the distance and decided it was too far, so we immediately canceled. It hadn't even been booked for an hour. According to the website, it was free of charge.

Well, this letter arrived! It also clearly states that no contact with the companies is permitted.

What would be the correct procedure now and do I really have to pay for it?

Thanks so much