unable to get my cars registration documents

My vehicle was paid off in january 2015.i requested my natis documents to be sent to me.they never arrived.after numerous calls to wesbank it was clear they were not going to take any resonsibility for documents not arriving.they wanted me to pay an amout of R500 for new documents.i feel this is ridiculous as it is not my fault!i submitted a query and they never got back to me.now october and still no response and no natis!i am now unable to sell my car as i do not have papers.service is appalling and call centre extremely unhelpful and very casual about my predicament.they just do not seem to care about customer at all!i am at my wits end and furious over this!impossible to sell car which i need to do asap!