Consequences of TN Visa Denial

I work at a canadian IT consultant company, and was supposed to go to US to work for one of our clients. The company prepared my documents and I didn't do any proper research into the matter (Which, too late, I deeply regret). As it turned out, the documents weren't prepared properly at all, job descriptions were messed up, etc, and I was declined the visa on the basis of not having proper requirements. (Actually, I withdrew my application before it was officially declined, but my file was marked)

Now every time I visit US, I get stopped for a long uncomfortable talk about past TN refusal.

Is there any amount of time after which this scrutiny at the border will stop? Is there anything I can do to stop it and may be even clean my record? Are there any consequences that I'm yet not aware of? For example, they ask me to state where I work; If I ever become unemployed, will I be denied US entry at all?
Also, If I ever want to work for a different US company, will it be possible to get a visa?

The scrutiny at the border will likely continue. It is the function of immigration to investigate. Perhaps you should seek a border crossing card. No one can determine the future decisions of immigration.