I used to make custom costumes and props on the side. One of my
most popular items was a pair of sunglasses based on those worn
by a character in a videogame.
A client ordered a pair, and I made the mistake of packaging
them when I thought the paint had fully cured (it hadn't -
completely my error.)
When she got them she e-mailed me to let me know she was upset,
but also that she found the frame modifications unsatisfactory
so she had further sanded, cut, etc., all before she contacted
me. I would have gladly made repairs and adjustments at no
charge (I have done so for other clients.)
Even then, I offered her a full refund if she sent me back the
sunglasses, figuring I could salvage them for future use and
make a better go of it next time. I even offered to cover all
shipping fees so that she wouldn't be losing out on any funds.
She refused the offer and opted to keep them.
OVER A YEAR LATER she e-mails me (trimmed for length):
"...I think this item is a total and complete rip off, and the
worst money I have ever spent. The first time I complained you
never offered any money or anything, but if you do come to your
senses and are willing to offer me something, or even to send me
a new pair of lens, I have a pay pal account or a shipping
Right. Because I made no such offer. And because refunds on
custom work are TOTALLY valid after the item has been in your
possession for over a year.