Conflict Listing New Products with GTINs

I haven't been able to list any products on Amazon since signing up in December. My GTINs are conflicting with the ASIN of another company's picture products that aren't even in stock and I have been going around in circles providing my issues and evidence of my branded product. It seemed as if I was getting help but the latest request was that I need to choose a different SKU for the product as it is conflicting. But now my account is coming up inactive even though my card is activated and I cannot search the product database if I want to check whether a SKU already exists. Can anyone help and shed some light on these issues. It is absolutely shocking that I can't list any products and have bought GTINs but they cannot be used. I do not know what the workaround would be as I have registered as a brand.