An agent fraudulently made me guarantor for a person I dont know

I was looking for Home loan self a few years back and contacted an agent to help me out. He took all of the documents as he said will apply in all banks. I visited a Bank along with him a few yrs back and signed few doc assuming applying for a loan, but later on found i am gurantor for a person who is unknown to me. I was unaware that i will be guarantor for this home loan while signing few docs via that agent at bank branch. Somehow I managed to contact the said person and requested him to get my name removed and he agreed. Later on he sent request email to bank for removal of my name, but no action was taken. I submitted a request in Public Grievance System of the Bank and got a positive response as below Requested On : 10/5/2017 6:41:32 AM Response : Had a word with the customer, he is ready to change the guarantor at the earliest. Yet now thats not been removed and when again I submitted request they are saying the account is NPA and cannot remove name unless dues are paid. What should I do?