I work in a charity shop and we do have a refund policy, its on our receipts and its displayed in our shops, we will refund anything apart from books DVDS
and CDS (unless faulty) as long as our ticket is still attached to the article and as long as a customer has the reciept we dont quibble at all however we do have to ask for name and address (company policy to ensure the staff and volunteers are not putting through false refunds and pocketing the money) and that sometimes causes disagreements.
As f[pr haggling it really does depend, I had two people do that today both on bricabrac.
One item we had in our shop for three weeks and I was just about to rotate it to another shop, so I did go down a price point for a customer.
The other one was classic
Chap wanted a picture in our window (Hove to the Needles by Roger Desoutter) I know just how much to charge for that depending on the print and the quality of the frame, they never hang around for long, bought by both Islanders and Tourists.
He said it was too expensive and tried to beat me down, as I had only just priced and displayed it I said no sorry no can do, he was rather rude and told me to stuff it.
An hour later he came back wanted picture after all only we had sold it (for the asking price) 10 minutes after he left the shop he was NOT happy apparently I should have kept for him in case he changed his mind - stupid man