I think this is very sage advice. And... difficult to do, but verrrry effective: If you want someone to stop bugging you for money (especially while they still owe you money!), ASK FOR YOUR MONEY BACK. Each and every time they call you, you should ask, "Oh, I need my money back." .... "That's great - I need my money back." ...."I need my money back - when should I stop by?"
GUARRANTEED to make them STOP CALLING YOU.
You might have to resign yourself to having lost the monies owed you so far because those people will evaporate... but in going forward, your answer should be : "Oh, I don't have that right now." Of course, the short answer is simply, "No." which IS a complete sentence, but often very difficult to utter.
I'm thinking your thread title could have been more appropriately entitled: "People think I'm rich and will give them money, because I am a tenderhearted, soft touch."
Good luck - Your money should be enjoyed by YOU.