NDA won't cancel my application

I have been trying to cancel my application which was provisionally approved since the 06th of February. I have written countless emails and sent text messages to a senior debt advisor Sinoyolo Sebhuza but NDA refuses to cancel my application. I spoke to a consultant by the name of Amanda on the 25th of February after failing to get through to the cancellation department and she said she can see on their system that my cancellation is still pending because I had not yet been fully approved and had not yet signed form 17.2 and a senior adviser by the name of Riedwright will be contacting me soon. To date no one has contacted me and my application is still not yet cancelled. What would it take for NDA to cancel my application?