I assume your camera has auto exposure. Make sure it is pointed at a darker portion of the picture and not the light or reflector when you push the button half way down to take the reading. You can then move it back to what you want to photo and press the rest of the way down. I hope this doesn't insult you, but some people don't know this. It works the same with the auto focus.

Otherwise you may have to take your camera out of auto mode and go into programming your own exposure and aperature.

Otherwise turn off all the lights and use the flash.

Otherwise throw the camera away and get a better one.