Amazon.com Amazon Marketplace Inability to receive a refund promised Nationwide

I ordered FW1 waterless carwash with Carnauba through Amazon.com in May 2014.  The product came from International Goods in June 2014.  The product received was not what was pictured on the website.  I called Amazon.com on several occasions and wrote an email to the Company through the Amazon.com website in an attempt to return the product.  I kept getting promises just to get me off the telephone.  Trying to get a return label was impossible through Amazon.com because it said the item couldn't be shipped through the mail; however, I received it via UPS.  Finally, after repeated attempts, I contacted American Express to let them know the situation.  American Express credited the amount and attempted to get the situation resolved.  They kept getting bogus information concerning my order.  I kept responding to American Express and they kept writing to Amazon Marketplace about my inability to get a label to return the product.  Finally, on October 8, I got an email from Amazon.com with a label for me to return the product and was told I would be reimbursed for the postage to mail it back to International Goods.  I mailed the product back on October 9th and International Goods received it on October 15th; however, I have never received a refund of the $29.54 in postage to mail the product back.  I feel that I should have been supplied a UPS shipping to be able to return the product.  That is the way the product was shipped to me; however, that didn't happen.  My attempts to get the refund of my postage have been to no avail.  I keep getting the same run around.  American Express did tell me that they finally received a credit to my account from International Goods just recently; however, my contact with Amazon.com to received the refund of my postage has been fruitless.  All I got in response was chastisement for having contacted my bank regarding the situation; however, if I hadn't contacted my bank, I feel I would not have received the refund amount from International Goods.  I had to wait an excessive amount of time after they received the goods to get that processed.