Deposit

I know it’s been a while, but I didn’t realize I could get help on Reddit.
In short: I rented this apartment but moved out early. According to the contract, I found someone to take over my lease (if I hadn’t found anyone, he would have charged me €289 for the early termination). Therefore, my account balance is €291 (€289 refunded + €2 credit from the previous top-up).

My security deposit was €309. He was supposed to transfer €311 to me in October 2023, but it’s now 2026 and I still haven’t received the payment. I’ve emailed him several times, but he hasn’t replied to any of them.

What can I do to get my money? I’m attaching a screenshot of the PDF document stating that he will transfer the money to me.

And another funny thing: Every few months he sends me a promotional email to find tenants for his apartments, and he gives me 25 euros, but he doesn’t reply to my emails.