It seems like you pretty much figured out your situation already. But I can't help wondering, why don't didn't you try and resolve this issue with Stevens? They even called you back and tried to get you to come back...just seems weird to give up like that.
If you trained through Stevens to get your CDL they will come after you for the money you agreed to pay back in the contract you signed. Your counselor should have been keeping in touch with you weekly so you need to speak up and let them know what happened. I started with Stevens and was pulled off TWO trainers trucks before getting the right one. When I came to the yard they asked me to write down the issues. I never had to see the other trainers again. I do know they didn't last long as trainers after that. The right trainer makes the difference. As for counselors try Max Bronson. He's one of the good ones. Good luck.