Chargesheet

I have been issued a charge sheet by bank for some irregularities. I disbursed a group loan containing 5 clients few months ago. In the day of disbursement when the clients arrived office I was outside office for some official work.I asked our general purpose stuff to take their signature in disbursement docs. After few hours I returned from field and found one client has left office before my arrival.The GPS and the other group member informed me that she left office for her personal problem after doing her signature.I verified the docs wheather all signatures has taken or not.Found ok and I disbursed the loan in system.but I have not tallied the signatures between pre sanction docs and disb docs.After few months it has observed that there is signature mismatch of the client who left office before my arrival. Signature of pre sanction docs and disb docs are different. Signature of disb docs is matching with her daughters signature. Now HO claimed that I have disb a group loan without taking proper client signature.The client has not arrived office but I disbursed the loan. Also claiming I have done that for my vested interest. Also claiming I have misuse my position by asking the gps to take the signature as he can not take such signatures. Please inform what will I replay