Airco Installer Stole Deposit

Hello, apologies for being in English only.

Last year I found an air conditioning installer with good reviews and asked him to install an air conditioner in my apartment. It went well, so I also decided to install a heat pump, for which I paid a deposit for the equipment (more than €2k) that was back-ordered and would take a couple of months to be delivered.

I followed up a few times, but at some point he stopped responding. I eventually took some templates from the Jurisdisch Loket and sent multiple letters (via registered post, email, and WhatsApp), first reiterating the agreement and giving him two weeks to respond, then stating it would be terminated if he did not respond, and finally stating it was terminated and demanding the deposit be repaid (e.g., this letter is one). He never responded to any of them, though I see he read my WhatsApp messages. He does not answer my calls either.

His business is now listed as "Permanently Closed" on Google Maps and he has suddenly gotten a lot of bad reviews on Werkspot, so he is doing this not just to me. The business is still registered at the KVK, as an eenmanzaak.

What are my options now? I looked into the Dutch small claims process, but it seems that, since I cannot speak Dutch fluently, I would need to hire someone to represent me. This is of course possible, but expensive, and, if he is unable to pay (or I lose the case for some reason), may just mean that I have spent even more money chasing down bad money.

However, it's not an insignificant amount of money, at least to me, so I would like to get it back. Any suggestions?