Amazon Refusing Refund for Cancelled Watch Order

I bought two Rosefield ladies’ watches via Amazon in England on 6 June and paid for both items. Shortly after, on 9 June, I cancelled one of the watches, which was the gold model with a white face costing 129 euros. I received an email confirming this, but to date the refund has still not been returned to my account. When I contacted Rosefield, they informed me that Amazon is responsible for issuing the refund. However, when I contacted Amazon customer service, I was told to contact the seller. I am therefore stuck between the two parties without receiving the refund I am entitled to for the cancelled watch. I request that a refund of 129 euros for the cancelled gold Rosefield watch with white face be issued immediately to my original payment method and that I am clearly informed once this has been processed.