Ignition Lock Defective - contact workshop - no ignition, car is a brick

[paceman]

Hi all,
Late 2008 A4 B8 Avant - 120K.
This is proving to be a nasty problem. Last week, car refused to start, on a later attempt a warning appeared on the dash.
'Ignition lock defective - Contact Workshop' This is different to the yellow key warning that some people have reported.
The result, can't even turn the ignition on. Putting the key in the 'slot' and pushing once results in a click, but the key is not retained.
Replaced the battery in case that was at fault as it was old and we were getting warnings that it was low on regular occasions. Didn't make any difference.
I removed the ignition switch, stripped, cleaned and refitted - no difference.
Got a man with a laptop out, he plugged in, but wasn't able to deduce much as you can't turn the ignition on. Said he'd need to get to the garage. Cue AA visit, he got no further than the other chap, but did disengage the electronic handbrake and towed it to the garage.
Garage have replaced the ignition switch with a new part - no difference. Garage seem out of ideas.
I've done more research and found mention of issues on Passats that are caused by the Steering Lock Control module - but none seem as critical as mine is. Interestingly, the steering lock was not engaged. Can't find anything about this happening on an Audi.
I've ordered a second hand Steering Lock Control module, which will hopefully arrive with the garage tomorrow. If that doesn't do anything, then it'll be replacement Comfort and Convenience module (if I can find the right one).
I'm aware that the modules will need 'programming' to play with each other, but I'm hoping that an un-programmed module will at least allow the ignition to be turned on so the garage can use VAGCOM properly.

Does anyone have any other ideas? I'm loathe to go to Audi as I'd need the car towing, and the resulting Audi bill would be significant.

Thanks in advance!

Jason

[procomm]

Hello, I have just had this warning occur having got home after Audi had done mot and interim service, have you managed to fix yours and if so what was it? Unfortunately my car is going in for some insurance repairs tomorrow so can’t take it back to Audi till I get it back but I have informed them but all there technicians had finished for the day