Do you guys return wrongly given change?

Most of us are drivethru veterans. What happens when the mistake is IN your favor? Do you go back?
Actually yes, I do.

If you don't return the extra change and you don't go tell them they gave you 3 extra burgers, why?
I return extra change, actually, and there was a day where they gave me extra food on an order. I was in a drive thru...found it before I left the parking lot...I went inside and showed them the receipt and pointed out that I got more than I paid for...and they smiled and told me it was their mistake, and to enjoy it because they can't touch it once it's left their hands and been placed in mine.

But they DID thank me for my honesty.

In fact, maybe you had plans for that female, sold as being not gravid, and now they were interfered with because she turned out to be gravid. Now you can't pair her with YOUR male.
This was actually what I thought of when I read the original post, since I kindof want to get a mature female to breed my big male to and would be VERY upset if I bought a female who then laid eggs.

Now this REALLY gets to me, why would whether or not you 'like' the seller have anything at all to do with it? Do you have two different sets of moral codes? One for people you like and one for people you don't like?
If someone hadn't already gone there, I was gonna. Sorry to say. XD