Lapsed Policy due to incompetency!

Since from February this year I've been trying to get Sanlam Sky to update my mother's so that I take over the monthly payments and up to this day it has not been done. My mother is on retirement, that is why I am supposed to take over the monthly payments. The policy has been active for over 2 years. I have called Sanlam Sky several times since February and everytime they tell me that the policy has lapsed and I submitted the Bank Details Change Form back in February. Instead of giving me a definite response I am always told by their phone consultants that they are going to seek advice from their superiors but they never revert to me. I've spoken to 3 people from Sanlam already about this and none has ever reverted to me to give me an update on the matter. Sanlam customer service is very bad. The name of the people I've been speaking to are Magnus Banda, Angelica, Thato and as I am writing this I am speaking to another one by the name of Pelandah and she still promises me that their Manager is going to investigate and revert which I know will never happen.