dangerous goods exemption sheet declined constantly

im so worn out , been on the phone for 5 hours so ill keep this short ,

-I create a listing for one of my products (power bank) which is just a variation of a current product of mine

-I submit exemption sheet with all information that is required, its the exact same as the variation that was accepted as its only a colour change except from asin and title .

the document is accepted and im cleared to sell it on amazon fba ,

i send in £2000 worth of the stock and it gets accepted within amazons warehouse

in a couple of days after selling about £200 worth amazon goes back and declines my exemption sheet without any reason told to myself and tell me they will destroy my inventory

this is where I am now , I have been constantly contacting support and getting the same copy and paste response except from one agent who barely spoke English and was typing random response that didnt make sense .

can anyone help me at all ? not only would i be losing this money in stock but i have more ready to send in.