Brought my computer home from a repair shop in worse shape than when I brought it in - tips on handling this?

So I did something incredibly stupid about a week ago. I didn’t look while inserting a memory card into my laptop and I put it into the adjacent slot, which happened to be the CD drive, and it got stuck. Herp derp.

I would have felt fine opening my computer up on my own, but figured that would void the warranty, so I brought it to a local shop. They took it overnight, in which time they took it apart and got the memory card out. Hooray!

Except not really, because I started noticing problems after I got it back. Namely, the power button, which usually is lit, isn’t, and about one time out of every 5 when I press the power button nothing happens. So I haven’t shut it down in ages because I don’t know what I’ll do if it’s shut down and I go to turn it on and nothing happens.

I’m going to bring it back to that shop tomorrow and tell them what’s happening. Is it reasonable to hope not to be charged for them to fix it since it’s obviously their mistake? I know I can’t prove that this just arose after they worked on it, but I hope they will be accommodating. If they’re not, what are my options?