First Timer – Error 5461 Help Please

First time trying to put a listing on Amazon (AU). Private label. Do not have brand registry. I see that it’s possible to apply for brand approval without brand registry. So I applied for this product and received an error 5461 email a few hours later. It says “In this regard note that ASINs for the requested brand “….” already exists on catalog with different product types.” I sent them a reply, asking if the problem is the EAN barcode I provided being already registered, or the brand name I am trying to get approval is already registered. Which one should I change to get rid of this error? Their reply is “Please note that this error will not be resolved, even if you change the Product ID and brand name for the same.” What the hell do I need to do then? There’s nothing on just brand approval on Amazon. Only brand registry. I search the brand name on Amazon, nothing comes up. I don’t know what Asin they are talking about. I am super frustrated and desperate at the moment. Please help.