Software update for Power Steering - not happy !

I had the car (New A5 TFSi) in for it's first service a few weeks ago and they informed me it would need a software update for the power steering.
I asked what the problem was (as I love the light / sharp feel of the steering) and they said there was a problem at the dead ahead in winter conditions / below 0 degrees C.

After the service / as soon as I picked the car up and drove away I hated the new feel of the steering - it's far more weightier, and nowhere near as nice/sharp as before - especially on a B road. My fuel economy has also gone down by 2 mpg (I do the same journey every week and have constantly monitored it over the first 10k miles).

In the month since the service, on one day the steering feel went back to "normal", but unfortunately it reverted back the next day and has been the same since.

I rang the dealers and they said there should have been no noticeable feel to the steering and hence it went back in today to be checked. They couldn't find any problem and can't revert the software update - GRrrrr.

So it appears I have to just put up with this - i'm not at all happy.

Really annoyed at this - anyone any advice on what I can do or has anyone else had this update and noticed any difference?

It's going back in on Monday for them to have another look and they're giving me an identical one to take for the day in its place.

Nothing they can do about my car - the software update basically adds more weight to the steering in the dead ahead position - I don't like it but have no option than to put up with it.