Not the correct weight

We bought Cape Point Platter Prawns from our local Checkers today with 700 gram marked on the outside of the box. After defrosting these prawns the weight was exactly 440 gram. Why misleading the public by advertising your prawns at 700 gram if that is not true. I have been a loyal supporter of Checkers but I can assure you that I will never ever buy seafood from Checkers again.