Pilot assist struggling after replacement windscreen

[Torshen]

I love Pilot Assist. I use it all the time, especially on motorways, and personally find it fantastic. I've used it in all weathers, in all lighting, in pretty much every driving condition there is and I've been really impressed by how well it works for me and am very familiar with it.

Yesterday I had the windscreen replaced by Autoglass and these days as part of the service they also recalibrate the cameras and safety systems after doing the glass.

Driving it today on familiar roads (little bit of motorway, some dual carriageway A-roads, some smaller roads) and using Pilot Assist where I normally would I can see it's not behaving the way I'm used to and the way I'd expect. It picked up the lane markings a couple of times but only ever held them for 5 seconds or so then lost them again, and the markings are decent plus these are roads I've driven plenty of times before and know it handles them fine.

Now obviously I need to call Autoglass, explain the situation and give them a chance to put it right but here's how I'm anticipating it'll go (feel free to label me a pessimist)...

• I call them and explain.
• They send the same guy round again.
• He does the same calibration again and hands me back the vehicle.
• I take it out for a test and discover it's still not working correctly.
• I call them back and explain again.
• A cycle then ensures with a number of repetitions, before...
• They start saying things like "well sir these systems are never perfect and it does pick up the lanes sometimes so we believe it's working as well as it should."
  And then I say "no, I'm very familiar with the function and I know it's not as good as it used to be."
  And then they say "well we've done all we can, and it does work, just that it doesn't always recognise lanes but that's what we'd expect."
  And we go round and round like that.

Obviously if I take it to a dealer they're going to charge me and I doubt Autoglass will offer to pay for that so while it's an option it's going to have to be a last resort I guess, as I'll end up shelling out for it.

So before I go into the customer service loop outlined above, does anyone have any advice or tips or whatnot?