BUY Misleading Promotion and No Customer service Aliso Viejo California

I ordered a book from BUY.COM using the promotion from their site, which says 10% off Amazon, plus get free shipping.

http://www.buy.com/toc/10percent_Off_Amazon_Promotion/58711.html

It says "plus free shipping" and "Start shopping" . It did order a book which was nearly $12 more at Buy.com compared to Amazon. I also choose free shipping.

Once I filed for the refund for this promotion, they say I used "free shipping" and this promotion cannot be used.

If you read the FAQ in the promotion page I posted above one of the question is

Q: Can I get Free Shipping on my "10% Off Amazon" book order?
A: Free Shipping is available on qualifying in-stock books and book orders over $25. However, you may not use Free Shipping with your "10% off Amazon" order. Click here for Free Shipping details.

Why does it say free shipping available and then say you may not use "free shipping" with this promotion?
When infact free shipping disqualifies this promotion completely?

And why did they post "plus free shipping" on top where everyone reads it? when there is no "free shipping" with this promotion?

a) you can only use either free shipping or this promotion but not both of them together.

I asked them to change the free shipping to standard shipping and process the difference and they say they cannot even so that as they cannot change the order.
They do not have to change the order that is already shipped, just processing the refund factoring the shipping cost; which they refuse to do either.

They suggest I refuse the shipment and I notice that the price of the item has gone up on Amazon.com now.

Misleading and No customer service...

GVS
Cheswick, Pennsylvania
U.S.A.