Never come across this before.
I saw an item with a buy it now price or make an offer. I made an offer £2 below the buy it now price (£12) and it was rejected. Fine, no issue with that at all. I left it a couple of days and decided that I would buy it anyway and bought it at the buy it now price and paid immediately. They are now refusing to send me the item as I 'insulted' them by making an offer. They still haven't refunded me either. I had someone offer me £2 for a £15 item but I just rejected the offer and thought they were a chancer but that's it!
I've been in touch with eBay but I just wondered if anyone else has come across similar bat-shittery?