At the moment I'm consulting with a debt collection company from Ukraine to recover the debt. (With interest of course!)
Why are you bothering?
Just send them the formal demand for payment, wait 10 days, then file a claim online through the e-court in Lublin. If they don't contest it (and it's unlikely they will if it's a clear cut case) - you'll get the positive judgement through within 3-4 weeks maximum. Once that's through, appointing a baliff is a formality.