Last year i was overpaid at work, i was bullied into signing…

last year i switched positions within the company to a commission based position. my contract stated as a trainee i would recieve $6000 guaranteed commission/month and a salary of $3000. When I rrecieved my first pay, my pay stub stated "base pay" $3000 and under commission it said $6000. I was paid in this way for 5 months before finding out they had made a mistake and this was not the way it was supposed to be. They were overpaying me $6000 per month. Unfortunately I had no way of knowing this was incorrect while it was happening. So the total overpayment was $24000. For the past year they have been taking all my commissions made to repay this amount, they have ignored my repeated attempts at asking for clarification on how much has been paid down month to month, as it was never seen on my pay stubs. Now I still have no idea how much is owing. I would like to know what I can do, I constantly am given a run around by management, that they are going to "look into it" and will "get back to me" but this has been happening for months. I have run out of people to contact. I completely understand paying back what was overpaid, but I cannot continue to live on very little with no understanding of where every sale I make is going. It seems to me this has not been dealt with properly from the very start, it doesn't seem right that they don't need to tell me how much I have paid back each month, and it doesn't seem right that I can never get a straight answer from anyone, if I am able to get anyone to return my calls at all. I'm wanting to know how to deal with this, so I can stop living in limbo wondering when this will be over.

I have a contract as a saleman, but no not a union