Dug out my Alarm System Instuctions,which is what I shoud have done in the first place but I had forgotten that I had them.As I still remembered the PIN it took a couple of minutes to reprogramme the duff key.And of course the one that worked as reprogramming the duff one would stop the good one working. **1234*91*2# then press each key button..
Incidentlt Autokeys confirmed their £580 charge.