The interesting problem here is philosophic. On one level, you have a
moral (ethical) issue. On another level, perhaps deeper, is your entire
concept of what life is all about, how you want to live your life, and
what you hold as the purpose of your life. Probably why you`re losing
sleep. :-)
I`ll propose that all of us have two categorical ways to look at all of life
and our purpose here. We have to choose one of them. The one is to simply "get through it." In that
view, life is a series of reactions and responses to circumstances,
fortunate opportunities, wishes and hopes, and accumulation of wealth.
The other is that life is a platform of some kind for a purpose. In
this other view, all of history and human culture generally suggests
that there is a basic purpose to each life, somewhat like a "destiny."
The evolution and development of some type of ongoing aspect of "self"
learns and experiences each life, developing in some way.
Following each basic view, all of us develop rules and principles of
how to live. Each of use chooses a morality based on our philosophy.
That morality can be just about anything, but with thousands of years
of history, most moralities have been described and listed.
If you see things the first way, that life is a set of reactions, then
your logical solution is to let the transaction stand and deal with
possible consequences if or when they arise. If nothing happens, you`re
no longer involved. If something happens, you worry about it at that
later time.
On the other hand, if you follow the second category, then you have to
evaluate both your business and your own personal "quality of self."
Speaking to your buyer and indicating a less-than-promised (or optimal)
product will impact your business and your cashflow.
One possible outcome is a request for a complete refund. The
consequences of that could bankrupt your business, or it could
introduce a level of respect for such abstractions as honesty, customer
satisfaction, reputation, and so forth. The gamble is whether your
buyer values these kinds of abstractions.
An argument toward the refund would be that if your business bankrupts,
"at least" you can live with yourself on a character level.
So the bottom line question is this: how important to you, on your own,
is this sense of your own character? Which will you choose: practical
business, or a risk that your buyer doesn`t assign value to character
abstractions.
Saying the same thing in common language we hear every day, you`re the
one who has to look in the mirror every morning or evening. Would you
rather pay the bills on the basis of a low-quality product, or lose the
business (possibly) or struggle with the bills on the basis of your
vision of some concept of character.



