Immobiliser problems

HELP!!!
Female land rover owner with an incompetent mechanic!!!
I have a Discovery 3.9V8i R reg. Last week my also imcompentent boyfriend changed the plugs in it. he put the leads on the wrong way so the engine was mis firing. When he rectified that fault the car ran ok for a day but with a loud rattle. the next day it wouldnt start, wouldnt even turn over. the key fob is not responding, there is no central locking and the immobiliser cannot be disarmed. i think the buffoon of a boyfriend has knocked something when he did the spark plugs. The mechanic that the car was towed to just keeps saying that he doesnt know what is wrong with it. i have tried the emergency key access code in the drivers door but it has made no difference.
Can anybody help me? four kids under 10 on public transport is just not funny!!!!

Hello and welcome Karen
hope you manage to sort it, know what you mean bout public transport with 4 kids

turned out that it needed a new key fob, the other one was totally burned out and the emergency key access code was the wrong one!!!!
car still misfiring and there is no power to it at all but none the less it drives! thinking i might send it in to the garage for a complete service and check up