Hi there folks. Wonder if someone can help me out here. I have taken an old ceiling light down and when I was unscrewing the wires on the old light I didn't check which wire was where. I am now left with 3 grey cables each containing a green, red and black wire. I thought that I just had to screw the 3 black (twisted together) into the black on the new light, same with the red and same with the green apparently this is not the case and when I turn on the circuit the light is permanantly on whether the switch is or not. I think I am doing something basic that is incorrect. Can anyone help please?

Without knowing which wire is hot, neutral, or switch leg, you will need to use a voltage tester to determine which wire is which now. There is no way anyone here can tell you which is which.