No Response!!!!!

On the 11th of March 2016 we phoned the ***1 number was given quick service and a reference number ***6 with the promise that our query would be resolved within less then a week. Now a month later and no response has been received. We phone them on a weekly basis and they are fast to provide us with verbal confirmation but to date refuse to provide us with the written confirmation required in order to cancel the Cession on a Life Policy incorrectly ceded to Nedbank. I've spoken to various managers and still no response has been received. What more must we do in order to receive the required letter from Nedbank as they have confirmed on voice recording time after time that we do not and never had a bond with Nedbank and that the Life Policy should never have been ceded to them. I've given them until the end of the week for their written response before taking my complaint to the Bank Ombudsman for furhter assistance.