OK, here is a question for mechanics, I recently had my bike tuned up because the bottom bracket was creaking, now after 400 more miles it's back. Shouldn't the maintenance on the bottom bracket last longer than that?
I'm not a shop mechanic, but ... if and when I fix a creaking bb (presuming that's what it TRULY was) ... it stays fixed. Pretty much the same with pedals, cranks, chainring bolts, cleats, etc.
If they do a good job -- whether it be by cleaning, using decent grease, or the infamous teflon tape wrap method, AND they torque it properly -- it really should go a loooong time without acting up again.
That ALSO presumes that your NEW creak has the same cause as your OLD creak.
Quite often, that's not necessarily the case. Lookie here:
Hey, nothing infamous about the teflon tape fix! 500 miles on mine and no creaking. It works.
To the OP, creaks are very hard to chase down and solve. I suspect your LBS tried one option for fixing it, but it might not have been the right one. Or, as neil says, it could be a different creak this time.