been looking for a job for a while now, accepted and signed an offer of employment, went through all the police checks and whatever was required. did a pre employment medical test, I'm 25 and never once in my life taken a single drug or even had a puff of smoke in my life. i get to my first day of training and get pulled aside and told my offer of employment has been withdrawn due to the fact i tested positive for METH. WTF, I've never touched a single drug never even seen a drug in my life so this is crazy, company won't even let me take a 2nd test to prove it, any ideas or suggestions on how to handle it or where to go from here?