What kind of cleaners are good for laminate floors that will make them shine?

Hello there. About a month ago, my in-laws helped us installed Laminate Flooring in our living room and hallway. Everything went fine. In our living room, there was an indention in the floor where a wood stove sat. We braced and covered it, almost perfectly even. We did alot of test-walks/jumps/etc to make sure it would stay put and not move up/down. Shortly after installing the floor in our living room, I noticed a piece is coming un-snapped between two boards, about where that hole was. However, instead of bumping up (which is what it should do as the board would be higher than lower), it's sinking down. I've put an area rug over it and tried to arrange the furniture so that it would rarely get stepped on.. but it's getting worse. It is almost the last piece next to the wall, but we've already installed quarter round and it's smack dab in the middle of the living room. Almost the entire piece is popped out of it's neighbor piece (just on the side, not on the top or anything), and when touched/stepped on, it sinks down a little.. and I'm afraid it's going to snap..or something. Is there any way we can fix this without taking it all out? I can take a photo and post it, if it would help any. Thank you.