ABSA CREDIT CARD REFUSAL TO REVERSE FUNDS

Good Day

I need some Clarity regarding ABSA Credit Card. I accidentally transferred the incorrect funds into my husbands credit card (Of which I have signing powers on), he has called the credit card division and they say he is a defaulter and they cannot reverse funds. I have just checked the account and the arrears amount is R2457 transfer amount was R24000. Are they allowed to hold back any funds over and above the arrears or the minimal monthly payment?? We are willing to let them keep at least R8000 towards payments and continue paying monthly amounts. Kindly Advise