refusal drug screen

by john
(Blue island, Illinois )

I went to swift training academy the first day we took a drug screen I gave a sample but was ask to give another one while being observed because it was out of temperature which I agreed too it and gave it 5 attempts but wasn't able to go so they labeled it as a shy bladder and I was ask to go home and see my doctor and come back With proof of why I was unable to go or they was gonna put a refusal on my background... can they do that???

And can I still go somewhere else and get my cdl and get hired ???

Plz any information will be helpful