As someone who went a little KS nuts and maybe hasn't even opened their copy since receiving it, may I ask what replacement tiles these are?
E.g. just an error in your copy, or was there a general printing error that fixes are being offered for?
Some copies of Bomb Squad had modular board Control Frame's that were slightly too small to fit the Modular Building Tiles. This only affected playing the game in Training Mode and the first easy missions (where only two modular square tiles are set in the frame).