No feedback for over a month

I have contacted Standard Bank complaints department regarding my claim and was due a resolution in 8 working days. It's been over 1 month now and no feedback. I tried getting hold of the person who contacted me, the Team leader and the manager but they cannot even respond to my email. I even tried contacting them but they don't answer. This is the complaints department and they don't even get back to the customer, so who else can we complain to.

Below are the people I have emailed and called:

Karabo Thusi Complaints Specialist: Insurance Tel +27 (0)10 ********** / E-mail; **********

Team Leader: Martha Motsamai / +27 (0)10 ********** / **********

Manager : Lutendo Magadani / +27 (0)10 ********** / **********