Poor quality exhaust - worth complaining?

[ShampooEfficient]

My barge needed a new exhaust (cat-back) to pass the MoT - I was hoping for an advisory so as to be able to source and fit one in my week off, but it was too far gone.
They used their preferred fitting centre, being a V6 it needed two centre pipes and the back box - and to be honest, it's the worst exhaust I've ever had.
The sound is awful, it seems to rattle, and the fitment is far enough off perfect that there's only 4mm clearance to the chassis on one side, yet 30mm on the other. Hence one of the rattles...

I've fettled it as best I can, which has improved it, but it's still not right - and it still sounds bloody awful.
I'm intending on fitting a used OE exhaust to get me through, until I sort out a stainless custom one... that's how bad the current one is.

The MoT centre (my trusted one, after too many bad experiences) and exhaust fitters are about 30 miles away - which wouldn't be a problem if I didn't find the exhaust such a pain... I'd like to pop in for a quick word but the logistics are tricky.
Since I've only done about 60 miles since it was fitted, do I have grounds for complaint regarding the sound and poor fit of it, or am I likely to be wasting my time?

[Eunos]

ShampooEfficient said:

Since I've only done about 60 miles since it was fitted, do I have grounds for complaint regarding the sound and poor fit of it, or am I likely to be wasting my time?

Absolutely, make a point of calling down to them. Unless they're a bunch of absolute cowboys I doubt they'll tell refuse to fix it, especially if the fit is bad.