uktimberland4u.com uktimberland4u Purchased boots size US8.5, sent me a US9 Wide. Seller told me I can't return and to buy a US8. Internet

I purchased a pair of Timberland boots from www.uktimberland4u.com.  They offer the Chukka boot style in a men's US8.5.  When the boots arrived, they were a US 9 wide. 

I contacted the seller and they told me it wasn't worth sending them back due to shipping and customs fees.  They told me just to buy another pair in size 8.  They want me to buy two pairs of shoes, yet it was their mistake.  They are telling me they don't carry half sizes, yet they are available on their website.  I selected them by clicking on a link so it wasn't like I mistakenly asked for a size they don't even make.

I think this is terrible business.  They make the mistake and want me to purchase another pair of boots and fork out another $100.  This is a bad business and they shouldn't be allowed to take advantage of U.S. customers who aren't in their country and don't have a way to go after them.