I had a leaky M6TTL. After DAG threw up his arms in defeat trying to fix it and reproduce the leak, I sent it to Leica NJ for refurbishing or at least a thorough CLA.
It came back in a month... and it took a week to go back to its old ways.
This time I shipped it back after calling Tony, who was the repair supervisor. He said he'd expedite the repair, as I was leaving for Costa Rica in a few weeks. The camera came back in something like 12 days, and working fine.
However, six months later, it showed leaks again.
I sent it back to NJ, invoking their repair warranty.
A month later it came back... and (knock on wood) has worked like a charm.
Now, the Leica staff could have acted cantakerous, intolerant, snippy or downright rude, but they were always most cooperative, very attentive and quite nice to deal with. I have only good things to say about Dave Elwell. The few times I dealt with him (send him Leica questions and he'll reply right away) he was quick and helpful. In fact, he remembered my having mentioned a lens hood for my Elmarit 28mm (3rd version), and when he managed to get one, he sent me a note. Certainly, I paid some big money for a lens hood... but it was a brand new one!
On the other hand, I've heard all the horror stories... and they apply to Nikon as well! It seems nobody is free from getting a bad rap, regardless of their previous good deeds.
Sorry to hear about your troubles, Pablito.