Can We get the Natis documents please

My mother bought a toyota tazz a while ago using Toyota Financial Services. She paid it up in September 2009 and got a letter to say so. However she didnt know what she had to request Natis documents from them. Last year she sold the car to somebody else and now the ownership has to be transferred to the new owner. However the car is still on Toyota Financial service name even though its paid up. The traffic department wont let the car to be transferred to the new owner's name obviously. My mother has been going back and forth. We contacted Toyota and talked to one of the consultants who says we must get a letter from traffic saying the car is on Toyota's name. But he cant say what kind of a letter all he knows is that its from there. How will the traffic department know who was financing the car? My mother has sent an email to Toyota Financial Services on monday and there is still not any response and the new owner thinks we are *****s. Can you guys organize that these papers are couried to my mother so that she can put this matter to rest with the new owner please