Bad/poor/none Customer Service

Discovery Medical aid have pathetic customer service, im trying to change the banking details on my medical aid since July 2019. Today 28/08/2019 almost two months later and numerous emails that i have send to discovery customer service and still nothing has been done to this matter. The only response i get from them is the change of banking details form that i must fill in and sign. then i print it, fill it in and send it back then the same thing happen they send me the change of banking details form to fill in. I want this to be sorted out by tommorow the 29th August 2019 or i will go over to another medical aid..