Odyssey (164 Rivionia

I stayed a few nights at the Odyssey (164 Rivionia) and unbeknown to me, they demanded I pay a security deposit upon arrival that evening which I paid with my bank card. When I left, I asked that they pay it back and they didn't. I was given various excuses and to date, 3 weeks later, I still haven't been paid my money back. I however did get a call from the owner / partner trying to intimidate me and over my review on Booking.com - Now, they have even blocked my numbers and e-mails. I want want money back!