Close my account

It's been two 3months calling them to check the progress of my account cancelation, nothing is happening they keep on saying I must wait for the cancelation letter and it will be send to my email address even today no cancelation letter The account is paid up,but they can't close this account. Today 1December 2021 I called again they say I must pay R40.80 to close this account . I pay interest accumulating every month