They gave you a chain of custody form? Without any instructions? How big is the company?

We give out "new hire packet" which includes a background check (which we make them fill out and turn in) and the chain of custody form (the drug testing form) and tell them which testing facility to use. Our HR person can check online for the results. She's busy, but she will eventually get around to checking on all the new hires' tests, printing the results and putting them in their files. If there are no test results (failure to appear), she'll let the hiring manager know. They could tell you to go take the test, and you can't work until your results are back... it really depends on their policy.

Most of us will tell you the magic detox potions do not work, you only passed because of dilution.