Paid up letter

I have paid up my vehicle finance account in 2016. They provided me with proxy documents but they are unable to provide me with paid up letter. Currently i am unable to change ownership. I was provided with the reference no but whrn I do follow up I'm told that my matter is with legal department which thry are unable to link me with. I'm frustrated as this matter is long overdue. When I visit the branch they just refer me to the self service phone. The consultants on the phone just tell me that they will call me back but they don't.