Difficulty Cashing in my Unit trusts with Nedgroup Investments (Nedbank )

I recently completed a Withdrawal Form, advising Nedbank that I wish to cash in my unit trust fund account and have the full amount deposited into my Standard Bank account which I verified by including a copy of a statement showing the account number and my name . They refuse to do so,insisting that I visit the nearest Nedbank branch so I can be verified. this I have explained that I cannot do as I am overseas and approximately 8300 Km. away, yet they insist that this I must do They then said they would phone me but again refuse to call saying I can't be reached even though I explained they must call using Whatsapp or my international No. I hope you can Insist me in this matter.