About a month back I took my 5 string in because the bass control knob wasn't working and I found out that the pot had snapped off th pvc board it was attached to. Anyways, it took 5 weeks for them to fix it because the vendor they got the tone pot from fucked them around and I finally got the bass back today, after being charged $42AUD; $6 for the pot, $6 for a new 9v battery and $30 for labour, which I thought was a bit fucking much.
I got home and plugged the bass in and I thought I had my overdrive pedal plugged in but it was inside a box at the other side of the room, so I realised they'd fucked up the repair somehow because it sounded very overdriven and had alot of static in the sound, something which had never happened before I took the bass in.
I just got back from taking the bass back to the fucking shop and I do believe that I am going to be expected to pay for their fuckup. Do you think that I should have to pay more for them fucking up my bass?

Well, if it is certain that they caused the fuck up I would take it up with them. Because no, you shouldn't pay for their fuck up.

And btw, $30 for the labor is not at all unreasonable.