Debit order change to non FNB account nightmare

Hi, I have contacted the call centre on more than 5 occasions from 22 May 2020 as well as sent multiple emails requesting the form to change my banking details of my debit order. To date no form has been received via email from VWFS and the form is not available on the customer portal.

The agents insist that there is no issue with the email server and that I should check the spam folder in my gmail account. I receive my monthly statements and interest rate communication without issue from ***. I even provided my business email address to them as an alternative but no form received.

Please help as there will be no funds in my FNB account from June 2020.