If a guy agrees to a date to settle up then that is the day you agreed to so I would not even mention a word of the money unless WE gambled again where I would remark I am up X amount before we start this session. I have let people run tabs gambling for small money and over time it can pay pretty good because it adds up.
Have I been jerked around?, yes but rarely it has happened but if someone is an easy mark so to say then its easy free money anyway. One guy was a meth addict degenerate gambler, he was free money every time I saw him and he was a nice guy too. I forgave his debt because he cleaned himself up and doesn't gamble, drink or do drugs anymore so I am happy for him that his life is good now.
I think learning how to treat people is important in life especially when you are taking money from them playing a game you love. Maybe try buying them a drink, paying table time, shoot the shit with them, or even the good old free shot. I used to have a guy I gave 10/6 to and if he was really stuck I would say you are a good guy and I am going to give you a free shot at the cash, race to 4 or 5 even up. It is a lock and his chances of winning were very very slim but the guy had fun doing it, it was a free play for him.
I would not come on a forum where they are going to see and know its about them or be calling all week over $25 when I agreed to a date to pay off. It sounds like someone is either broke or a real tight ass nit. I wouldn't play someone either when they are chasing $25 hard like that either all week before our payoff date.