Do they live within travel distance?
This is so unfair...
I would try the "....the time has come for repayment now please beginning with the first installment on the ..... of October 2015. A fortnightly payment of $50 would be most appreciated, but I am open to discussion on the bi-weekly amount. Please contact me as soon as possible as to the method of payment. I am happy to have been of assistance to you in your time of need...."
A couple of years ago a group of friends gave me a leg up, I tried to pay them back and they wouldn't accept it. Whenever I am able now, in whatever way I can, I help folks out... it's not always monetarily. It helps me to feel better about my friends not accepting repayment.
He/she is not within a day's traveling distance, at least if he/she lives where he/she claims to, nor could I trust a physical address or feel safe visiting it.
I'd like to try your suggestion of contact but my experience has been that all attempts at communication by me are ignored. Of course, there was never anything in writing, just the word between friends. I understand now that it was all a lie, that the person was not about to lose their house and belongings. I understand now that it was a basic scam.
Most people, I presume, think like you and I do, Flake; most are not thieves.