Anniebach if it's been in the fridge for hours without setting there's no point in leaving it longer. Take it out and microwave it in a bowl, stopping to stir it every three minutes, then when it is a light caramel colour and beginning to thicken, take it out and beat it with an electric mixer for ten to fifteen minutes, by which time it should have thickened but still be pliable enough to spread back into the tin, when it should set quite quickly at room temperature. The texture of perfect tablet is crunchy and melt in the mouth, not soft like English fudge or hard and chewy like toffee. Good luck!