Everyone's probably sick of hearing about the issues I had with my Peugeot 407 (a C5 in a different skin).
I had a similar issue to you where the ball joints failed at both sides, and had to have new bearings (along with a raft of other issues).
Peugeot UK were just useless, totally unhelpful and just outsourced their customer care to some automated call centre who knew sod all. Some of the e-mails I got from Peugeot were actually quite hilarious as they knew nothing about the car or anything about Peugeot's stuff.
I ended up getting rid of the car (05 plate) as it was getting unreliable. However, before I did, I sent them a parting shot across the bow and reported a whole load of issues to VOSA who are following up on the ball joint failure because it was so serious (and common place) so they may force a recall.
That had been my 6th Peugeot in a row, but never never again. I now have a Nissan Pathfinder and my wife's 306 is soon to be replaced by an Audi A3
Good luck - you'll need it!