First National Bank
Transfer of Funds

I'm under debt review with Debt Therapy for the last - 4 years.
Included in my debt review is First National Bank - Overdraft account.
FNB receives a monthly instalment of R677.85 on this account.
On 8 February 2013 my brother in law in error transfered money into this account instead of my husbands FNB account.
Since the 8th of February I've been requesting FNB to transfer the money to the account it was meant for.
FNB informed me that I must contact Debt Therapy and work through them.
I contacted Debt Therapy on 15 February 2013 to request their assistance.
On 26 February Debt Therapy inform me that it's FNB's right to claim the funds. See extract from letter received from Debt Therapy: "FNB are in their full right to claim the funds, as the account the money was paid into is in debt to them, you owe them that money. So when any funds are paid into the account, it is automatically used for that specific account, especially if a client is under debt review, hence me informing you that it is going to take a bit longer to obtain the funds back, as the account it was paid into is under debt review."
What must I do to get the money transfered to the correct account. Please HELP!!