Oh god help.

I lent my former roommate 11.500 euro while we lived in Ireland and we have since parted ways, me back to Denmark and him back to London. He emailed me that the first payback would be on october the 1st. Nothing came, and he's not responding to emails anymore. What can I do?

I know his full name, and possibly what company he works for now in London. I can most likely find him on Facebook too, but I'm not on there myself.

I can maybe find his family here in Denmark.

The only proof for the loan is basically a piece of paper listing some numbers and then saying "Amount of money owed by X to Y: 11234 EUR", signed by us.