There are a few things...
Your story's pretty good, though the fact that Amy didn't get stung kind of bothered me. I get that you wanted to keep her alive. She seems like a favorite of yours. But that can't happen. Nothing changes. Both group A and group B are subjected to the same thing, and they reacted in the same way. The only change was the genders and Chuck saving Thomas. But that's all. Amy had to die. No question.
Read the story now
Also, did you base this on the movie? I think you did. In the books, the banishing doesn't work that way. There's one section of a pole for each keeper, and they put them together, forming one giant one with a collar at the end, which they attach around the neck of the person they're banishing. The keepers stand wherever their section is, then use it to push the person out into the Maze, letting one section snap off, along with the collar.. Your banishing is like the one shown in the book. One more thing. There was no 'first person' in the Glade. No. There were thirty or so dumped in there in the start. Not one. I really hope that you've read the books, your story is close enough to it that I have hope. But if you didn't then you should know that writing a fanfiction about a series without reading the book, only watching the movie, is a big taboo. You never do it. Ever. Oh, and they're called beetle blades. With a 't.'
That's all. All in all, you're a good writing, and you have much potential.