What do you do if you fail a drug test, when you have not done any drugs? May I take legal action?

I live in St Petersburg, Fl- There was a great employment opportunity available here at the Home Shopping Network. I went to HSN for the Interview, I was told I was the perfect fit, and the position was awarded to me on the spot ....per passing the drug screen. I made an appointment for my drug test- #Then 2 days after I took the test I get a call from the lab- A woman who barely spoke English and was difficult to communicate with told me that I failed the test and that they found Meth Amphetamine in my system! Ok- Now I am not an angel- I tried pot in the 90's, but that is the extent of my drug history. Something like meth amphetamine is so foreign to me- I told the lab it was a mistake- they asked if I had been on any prescription RX....I had not been- I work out a lot but... the only supplement I was taking was Phosphogen (creatine)- I immediately contacted HSN- Told them it had to be an error- They were extremely unwilling to hear the truth that is was a mistake on THEIR part..... They told me I can re-apply in 90 days. It has been 1 year - I reapply every 90 days, however they never contact me back. Obviously I am flagged. I feel victimized- frustrated- and it seems that there is no way to challenge their findings when I know that without a doubt they are mistaken. Do I have any recourse whatsoever- And if this has happened to me, it must happen to thousands of others....have any laws been passed?

The thing to do back then would have been getting another test immediately, preferably from a different lab, to show that the first lab made a mistake.

In theory, you would be able to sue the lab for negligence, damage to your reputation, and loss of an employment opportunity. However, the burden of proof lies on the plaintiff. Now that it has been a year, it is impossible to prove what you did or did not take when the test was administered.