Default HELP: Camera acting wierd!

I have an Alcatel One Touch Fierce and recently my back camera has been acting wierd, whenever I take a video if its a bit dark the video itself will get darker. if I'm outside its fine but in dim rooms its like the exposure sets itself to -100 and contrast to dark. If I move it to the window the video gets fixed and normal lighting. This only happens while recording, and when you save the video itself it saves the parts where it gets dark or back to normal when moved somewhere more bright. This started happening a month after I got the phone any ideas??? THANKS IN ADVANCE!