Amazon Brand Approval

Checking with anyone to see if there is a solution. We would like to sell a particular brand so we received the approval letter from the brand owner to sell and sent to Amazon for approval. They stated that we needed an invoice for the goods. So we went ahead and invested the money and bought more than 10 items of the same thing x several different items too. We then submitted the invoice along with the letter and still was declined. Reasoning from Amazon was to make sure that customers and sellers have the best experience (whatever that means). Has anyone had a similar response or issue trying to get approval to sell a a brand and supplied what Amazon has asked for and still been denied? Any solutions?