OP should consider the fact that ANY carrier with a USDOT number (even a terrible one) was willing to take a chance on you after a refused drug test as a gift from God.
I doubt anyone will argue that from here on out you'll need to be on the straight and narrow and be prepared to ensure some pretty heavy scrutiny (at least if their safety department has two collective brain cells to rub together.)
Keep your nose, and veins clean for a minimum of 7 years (hopefully with the same carrier) and you might be able to get into the good graces of reputable carriers.
Until then, you got some dues to pay and some lumps to take.