New Listing Error.

Hello guys, I was listing a new product I applied for GTIN on amazon and got approved and I am selling Generic cause I don’t have my own Brand, I put my own price and name and descriptions and bullet points and also Images and filled everything on the new listing and clicked on Save and Finish. After 30 minutes i went to Manage inventory to finish it, On my inventory there was someone else’s product, the product was the same as the product I am selling, it has its own SKU and ASINS also there is Different Images than I uploaded and the description And bullet points were changed as if I listed an existing product, I don’t know what to do should I buy UPC or is this an Amazon error, I spent hours on the listing cause it is my first product i am listing.