(T) Doblo Clutch slipping!

Seal problem.....hhhmmmm, this seems to be a common problem here as well. It seems the local agents don't know how to fit the seal properly. I've heard this complaint from several people. My Doblo was doing the slip as well in November last year, and soon started slipping out of second gear (about a week later). Was due for 100 000km (62000 mile) service anyway, so booked it in. Literally the day before the service, the gear selector broke. Towed it in, serviced, replaced gear selector, new clutch kit. When asked why the selector broke, I was told it was a part malfunction. When I picked the vehicle up, surprise surprise, still slipping out of second. Took it back, only to be told that the gearbox needs overhauling. No believable explanation as to why (many suspect stories: gear selector not engaging properly etc). Was told that teeth were worn. I am not the first owner of the vehicle, so no idea what the prevous owner got up to. I have only put about 50 000km on the vehicle. Luckily still under extended (private) warranty, but still cost me about 4 000 ZAR (about 200 pounds) which sounds heavy, but the whole job would have cost about 12 000 ZAR (about 660 pounds). I checked this cost with different gearbox specialists, and it seemed right. I was told the big cost item was the parts. Seems to be sorted, although I do get slight shudder very occasionally on slow pull away. There is a year guarentee on the gearbox, and clutch, so I will wait and see.