What happens if I got a garnishment of my wages for an old credit card?

I received a garnishment against my wages for an old credit card. They began garnishing 25% in Oct. In Nov, we had a hearing and agreed to a set amount of $125 per pay period. My payroll dept continued to garnish the 25% until now. They have made a payment to the law office representing the creditor. I am trying to recoup the amount that should not have been garnished per the agreement signed by the judge. I have spoken to the law office several times and keep getting a run around. Is there any legal recourse I have for getting that money? I budgeted for the $125, and now, I am behind on my rent and other bills and cannot afford to wait for them.