Hi, long story, left car into ball bag mechanic to have gearbox and general oil service, 5 weeks later come back and car battery dead and mechanic lost key!

He went awol so I had to get the car recovered as it would not start with my spare key. No buttons work on key and car won't unlock with the interior lock buttons etc

I removed battery under bonnet gaining access by using spare key in passenger door and this set alarm of. Car won't recognise the spare key and alarm keeps going off, ignition turns on but car won't turn over just one clock, immobiliser light flashes on dash.

It's like it has went on security lockdown mode!?

How do I get the car going again? Soo frustrating. Any help is very much appreciated.

Firstly, if the battery has been left discharged for along time, then it might well be useless. But first put it on charge for a good 8 hours, before trying anything. Then try opening it and starting with your spare key.

Update. Found original key battery charged up. Car unlocks with key but still won't start, just one click.