I feel I have done everything needed yet in a bottleneck here. I am trying to list a Costco version (bundle) of a Strivectin product. I got approval to list the brand, but I cant get past the ASIN/UPC issue. The UPC on the product conflicts some random mouse on Amazon. Amazon seller support has approved me to create a ASIN, but the status says declined, even though the message body says approved - and I cant figure out creating a ASIN other than trying to add the product - Each time I try to add a new product it says I must enter a GTIN. Amazon seller support said I should request my own GTIN through GS1, is that even allowed to create your own GTIN for a branded product? I'm obviously new to this and trying to do things right, but frustrated for 4 straight days with all my downtime chatting with Amazon seller support and trying endless. Someone please help. Would have been nice to get a knowledgeable amazon seller support on the phone, and I feel like trial and error for many seller support folks.