Abysmally bad service from FNB

Since March 2021 I have repeatedly requested that my bank account be closed. FNB advises that the only way to do this is for them to call me which they haven't successfully done and FNB keeps charging me fees on a monthly basis. How can you help me? Close my account? Or set up a time to call me in order to do this, none of which FNB has been able to get right over the past 3 months!