Mine was not communicating with the remote transceiver in the car. Found a place in Scotland online.
www.pixelsfixed.co.uk. Chap called Boyd Beattie. Extremely helpful. Suggested it may be the micro switches or circuit board inside the fob. I sent my key/fob to him through the post. He replaced all three microswitches and sent back recorded delivery for 38 quid (8 of which was for secure / guaranteed delivery postage). Had my key back within 3 days of sending it. Fixed my problem. I have the same issue with 2 of of the switches on my 2nd fob, so will be sending that one up too.