Home loan F R A U D

I am selling my house and the attorney responsible for the transfer is making a mess with the council rates clearance. This is now more than what I am selling the property for and she negotiated on my behalf (without my consent or knowledge) with Standard bank that I can repay the shortfall over 5 years by signing an AOD. I keep on telling her that she is wrong and needs to fix the problem. The attorney for the transfer and Standard Bank’s attorneys are now threatening me with legal action if I refuse to sign the AOD. I need to know how this is possible that Standard Bank and a third party can come to conclusions and make deals on my behalf and try to force me to sign an AOD that is not my debt.