DVD will not play !!!

[leig.tar]

I bought several films from a company but one wouldn't play. I contacted the seller who said it was a region1 US import.
I said that I did see that info on the item description before I bought it but that it meant nothing to someone who isn't technically minded !
I thought a US import just meant it came from the US and nothing more !
I asked for a refund with postage so I could return it but they refused saying I should know what Region 1 "implied" !!!
How would I know what that should imply ???
I've spoken to many people since both young and old who had no idea what it meant.
I've opened a dispute and am waiting for eBay to step in but they keep changing the date that they will help !
Has anyone experienced this before ? Any advice greatly appreciated.