Changing of legal ocuments after signature

I app**** for extension of existing loan with Nedbank. Loan was approved in principal - I needed to take my documents to a branch.I went to Nedbank Carlswald.Upon arrival Salome assisted.She hinted that I needed to apply for a new card ID as the banks will not take the original ID much longer.I rep**** that it is still valid.She completed the app and took copies of my ID and asked me to sign on the copy of my ID to verify it. I did this immediately below my id on the A4 paper. She send this to head office and advised they will reply shortly and could have the money in same day. An hour later I got an sms that my loan was denied. I called Salome to find out why. She advised my ID was damaged and loan got rejected because of it. I went back later to pick up my ID - was left at the branch -asked her to please show me where it was damaged. She responded that I was cautioned on a prior event-not true.I then saw the application sent to head office-she added a note below my signature after I signed that I acknowledge ID was damaged (Which it was not). I did not acknowledge this. She confirmed she added this after my signature in front of staff. ID not damaged. ******* changing after sign.