Amazon Support Sending me in Circles

Hi guys,

Trying to change Brand names on several ASINs due to previous sellers creating these before us as a Brand registered in Brand Registry and began selling. These sellers are known third parties and most have listed the wanted brand in another brand we own in Brand Registry.

I keep getting the below error message from our brand registry; “Due to the fact that you do not have a Seller Central account, you need to have an additional role added to your Brand Registry account in order to update detail pages.”

Can anyone help on how I link products to my brand?

Thanks,
Tom