Purchased a galaxy s3 for straight talk with cyanogenmod on it.

I bought a galaxy s3 for straighttalk from some one cuz it was really cheap. I want to remove cyanogenmod from it because the camera doesn't work and I can't save pictures. They didn't back up though so when I factory reset it, it brings it right back to cyanogenmod. How do I get the original OS for the s3 back on it? Im new to this kind of stuff so I didn't even know where to look on the forums here. And the person I bought it from is no help, I think they didn't even know how they really did it. Can some one help me or point me in the right direction please?

Sincerely,
Unmarked civillian

from xda-developers http://ift.tt/1WRCH9y
via IFTTT