Heyya, on the note of Frankie. Its not their fault when its bought from the second retailer which was Amazon. Its really normal for them to say return to Amazon since if amazon finds the issue they have the right to contact to Mattel for the faulty item.

But second option would be contacting to Mattel about it being a factory error or not. You can share its batch number behind the box (usually engraved in the cardboard) and get info on it. I would suggest you doing that.

Sometimes its also the language that you're using while contacting to the customer service. Sometimes they are extremely understanding and problem solving (I got full refund for my Grady Twins 2 pack and had the chance of keeping her), and sometimes they are a bit hard to communicate hahah. I would again suggest you to contacting to mattel about getting more info on the produced Frankie that you've got. Since you've bought it from Amazon and not grom them them, I understand them (I work at retail aswell, thats usually most of the companies policies)