Bent disc rotor

[deluz]

I finally got my Tarmac SL8 back with the warranty replacement fork.
When the fork arrived they asked me if I wanted them to install it.
Although I could have done it myself I said yes to avoid any possible issues.
I went into the shop to make sure they were going to cut the fork to the right height. There was no discussion of cost, my fault I didn’t ask.
When I picked up the bike they told me the cost was $265 which I thought was kind of high but I did not want to argue it and just paid and left with my bike.
Today I installed the new saddle and noticed the bike was really dirty with something that looks like it dripped down the bottom of the down tube, no big deal. Then I noticed a sound which was the front brake rotor bubbling the pads.
On closer inspection it looks like the rotor is bent and I am 100% sure it wasn’t like that when I dropped it off at the shop. I don’t really want to take it back as the mechanic there is super grumpy. I could buy a straightening tool and do it myself, but again I am concerned if something goes wrong then what? What would you do?