Unhappy Customer

I am due for a refund,which FNB confirmed that refund will be paid 26/03/2026.till to date the refund has not been paid.I have log 3 calls and 9 calls already still not getting the satisfactorily response.An agent said the refund is processed another agent has no answers.I have benn taken from pillar to post.They have issued my bank statement to prove that payment is not reflecting on my statement