Rejected several times - Product Group Approval Request for Kids and Baby Furniture

I am a new seller in amazon uk site and am listing a product which requires approval on selling Kids and baby furniture category. I submitted the required documents several times, with invoice of purchasing from manufacturer and product pictures of each side, but it still got rejected again and again. I asked amazon for the reason but got no direct replies or any suggestions on how to prepare the right documents, either try again or automatic rejected message. I do not know how to deal with it. Can anybody help me? Much thanks.