Wisdom in Repaying and Giving

Proverbs 3:27-29:

27 Do not withhold good from those to whom it is due, when it is in your power to do it.

28 Do not say to your neighbor, "Go, and come again, tomorrow I will give it"—when you have it with you.
29 Do not plan evil against your neighbor,who dwells trustingly beside you.

This is the first bit of human relationship piece of wisdom given. Proverbs has already mentioned that wisdom comes from God and that this will improve our favor with both God and man. Here is a practical example of this. The rule seems obvious, yet how often is it not obeyed. These verses are clear, if you have the resources (whether financial or otherwise) you should give it to those who it is due. I wonder if it is incorrect to apply this verse to financial contracts? Before the recession it was in style to have more debt than was usually socially acceptable and now it is becoming more common to walk away from the obligations of that debt. Perhaps the call is to simply be generous with the "good" we do in the present.