I cannot seem to cancel my policy

On the 3rd of June, I called into the Nedbank call center with the intention of cancelling my policy, because there is nothing in the WHOLE documents that tells me exactly how I can cancel my policy, and the lady whose name is Gwen said that I had to go into a branch to get it done. I found this ridiculous since I took this policy over the phone. So I sent an email on the 3rd to both [Email Removed] and [Email Removed] to cancel it. I got a response saying that my request would be processed within 8 hours. So today still not having received any feedback from them, I decide to call and use the tracking number I got from my email. I spoke to Thandi who informed that the email I sent was ineffective and said I had to fill out a form, send a CERTIFIED copy of my ID and it would take 10 days to process. This is preposterous because if my payment lapses then instantly I am not covered, but turn the tables then suddenly I am covered for another 10 days. I want this policy cancelled immediately and have my premium refunded. I will not be pushed from pillar to post and frustrated for your own amu*****t. This is the type of service my family would have got if I had died? No thanks!