If there has indeed been a mistake made by Fred, everyone's human. As he stated, this particular company has screwed up seven times, and that's only the times that Fred himself has rectified.
For what it's worth, I've been to two different Renault "specialists," BTM and JMS. And I'd recommend both to everyone else, I'll only ever use these two in future.
Eight. At least.
I had the belts changed on my 172 changed there.......... Needless to say if i'd have kept it Fred would have been fixing/looking after it in future.