I've had my bass for about a year, and ive had a tech mess around with it twice. i bought a new set of strings and i decided to take them off. As i was unwinding the strings, the (i think it's the nut), completely came off, the only thing that was holding the nut in place was the strings. the piece that holds the strings itself has signs of breaking, but what was underneath it looks like something may have broken off. there is also nothing for the screws on the nut to screw into, the piece behind it had screw dents but there was no hold or anything for it. i am in Toronto, however i am a little lost. How much could something like this cost me? is that piece supposed to come out when the strings are taken off? i am thinking maybe the tech broke it, and put it back without telling me. i am just unsure of what to do. Any advice would be appreciated. thank you.
EDIT
after looking at some pictures i can gurantee the bottom piece of the nut was missing, and just the top piece was strapped in, being held by the strings. I have a sneaking suspicion that this screams of a bad tech, but i don't know for sure. there is stil a very small amount of plastic where the first piece was supposed to be attached to. Is a repair shop gonna be able to get rid of that?
EDIT
after looking at some pictures i can gurantee the bottom piece of the nut was missing, and just the top piece was strapped in, being held by the strings. I have a sneaking suspicion that this screams of a bad tech, but i don't know for sure. there is stil a very small amount of plastic where the first piece was supposed to be attached to. Is a repair shop gonna be able to get rid of that?

