What must a person do to get a response from FNB?

ref:*** I have never received such appalling service from any institution in SA before. I still haven’t received a refund for a purchase done in NOVEMBER! I completed the dispute form, sent all the evidence on 5 different occasions but when I do receive a response from FNB (which is rare and you have to beg for), they say that they cannot help and ask for the same information again. I even emailed the CEO Jacques Celliers and not even the courtesy of a response. I sent a chaser email a few days ago and received an auto reply that the mailbox is full. What a joke! Worst decision I ever made was moving to FNB.