Beach Camera At Amazon.com review: Non US Product

I ordered a Tamron 70-200mm SP Di USD for Sony lens from Amazon.com sold by Beach Camera. I was assure by both Beach Camera, Tamron, and Amazon that Beach Camera is an authorized Tamron dealer and therefore all their Tamron products are US and have carry full Tamron warranty. However, when I received the lens which I had shipped next day and was paid for with an Amazon gift card and my Amazon credit card, the lens turned out to be what is known as a "Gray Market" lens. As a result Tamron USA does not have the lens serial number in its database and cannot honor the warranty. I was told by Tamron and Beach Camera there have been several complaints by Amazon customers that Amazon was sending wrong product and that Amazon should be able to send the correct lens with no problem. I called Amazon and I having all kinds of trouble getting correct lens. Amazon is telling me they cannot refund my account and gift card until they receive the lens and cannot guarantee that if I purchased another one from Amazon that it will be a US lens and not Gray Market!