Changing banking details frustrating

What’s so difficult about changing debit order details? I called in around May to change my debit order details and they assured me that it’s done but to my surprise it’s still not done. I also visited the Tzaneen branch in June to update my parents policy details, they were not willing to help from the minute I walked in and gave me an attitude. I was told that I need proof of account to change the banking details, I told them I have it on my phone and I can email it to them and they said they wanted a printout. I then went to my nearest bank to get a printout. They told me that it’s been changed but it’s still not changed when I check. I don’t know what to do anymore because my policies are about to lapse now. I’m so frustrated. I called again today and they placed me on hold for some time then just hung up the call. If I cannot get help over the phone and at the branch, who must assist me?