I can't hear the vocals on my songs.

Hi, this is kind of a long story. A while back I pulled my headphones out of my ipod touch 4th generation, and the bottom of the headphones snapped off into my ipod. I took it to the apple store to get it fixed. Unfortunately, I think that when I tried to get it out with my tweezers at home, I unknowingly enlarged the head phone jack whilst scraping at it. Now when I put headphones into my ipod, the headphones are a little wiggly in the jack. Also, when I listen to music, I can hear all the instruments except for the vocals. If I can hear the vocals, which is rare, they are very faded and sound like they're coming from a long ways away. How do you think I should fix this? Thanks.