Glm wrote:
No joy: they clearly weren't interested in helping further.
Said I could leave the bike there for ten days so that they could do
a 'full check-up'.

A 3 week old bike with mechanical problems and they aren't "interested" in
helping? Sounds like you might want to:
a) rethink the *reputable* label
b) find a new LBS

At the very least, you should talk to the manager/owner. If that doesn't
work, then spend your cycling $$ elsewhere.


Tom