Unsatisfactory/lack of response since Nov 2017

Absa notified me in November 2017 of a refund that is due to me on my vehicle finance account, and requested that I submit personal documents. Since then, whenever I enquire, I either don't get a response, or a general response that they are "working on it". All I want to know is how much is due to me and how long I still need to wait for it. I did not make them wait when they asked for the documents, why must I wait for a simple answer when I enquire? I really find this preposterous and appalling service very unprofessional for a bank that contacted me regarding the refund in the first place. Can I get an answer on: How much is due to me, and when I can expect this to be effected. This has been dragging on for the 4th month now. Totally unacceptable and frustrating.