I snapped the inner leaver on my left hand Mirage shifter (plastic) a couple of months back. Emailed Parker, sent it back, they sent it off to Campag and it arrived back in perfect working order a couple of weeks after I sent it.
Not ideal in that a) It broke in the first place and
I had to get some new shifters whilst waiting (any excuse
) and had the hassle of switching them etc. But good service from Campag.