Toyota Hilux GDE Bin not being water proof.

I purchased a Toyota Hilux 2.86 GDE legend RS with an expensive roller shutter mechanism. However on purchase they did not say it was just for show as we now find ourselves in a situation were we cannot store goods in the bin due to it not being waterproof.I get an email from Toyota Pinetown stating that there is nothing that they can do to repair. This is a highly priced top of the range vehicle how is possible that it’s not made to carry luggage or goods in wet weather. This is absolutely not acceptable and I refuse to accept Toyota’s response. Please be aware if you are in the market to purchase one of these vehicles.