Very Disappointed

I had a transaction deducted from my cheque account twice in error and the merchant told me to get FNB to reverse it for me. This has been my experience with FNB and I have still not had a single person actually look into the matter and be able to assist me since Friday, 5th Nov: I tried their secure chat twice, e-mailed the cards dispute department and made multiple calls to their so called 'help' lines only for each consultant refer me to another department. About R100 in airtime and 3 hours wasted time and I still don't have my money back in my account. I have been a client of FNB for many years and I am extremely disappointed with this service. I never resort to public complaints but I seriously don't know how to resolve this.