Hi.
Every interpersonal situation is unique in it's own way.
When people owe me and they don't make themselves seen I usually let them go. If they want to be mature and correct I believe it's something they have to decided to do on their own, without somebody else having to chase them up and prompt them.
I don't usually lend money nowadays, unless I know it's really essential for them.
That's just my oppinion anyway. At the end of the day you need to weigh out the pros and cons and make your own judgement. Sorry I can't be of more help.