Will Apple repair my iPhone for free or charge me?

I bought my iPhone 3GS about 4 months ago and I used to work in a plastic factory and one small piece of plastic got inside my headphone jack and I didn't notice, I wanted to listen some music so I plugged in my headphones but it didn't go all the way in and I pushed it harder to get it in and I didn't get any sound it was at night so I just decided to sleep, next day in the morning I checked why I didn't get sound and for my surprise I saw the small piece of plastic inside my jack and stuck all the way in since I pushed deeper.

So I want to call Apple to see I they can fix it but I'm not sure if they'll do it for free or charge me, I'm still under the original warranty but I don't know if it covers me in that case

Also the small piece has crushed a little bit and a part got out of the jack.

So does anyone knows if they would fix it or perhaps replace my iPhone for free or will they charge me and how much would it be?

Also my headphose got damaged from when I forced them to get inside the jack and now one of the speakers sounds awful would thy replace me the headphones too?