Request for refund

Hi Standard bank group. I really hope i get the assistance as your client. I have been weekly depositing to my VAF account and the difference is debited on the 25th of each. In the month of June an extra amount of R5000 was debited hence i requested a refund on the 10th of July. That refund was issued to paid out on the 30th of July. Till today i have not received that amount and all i get is a promise to be called back by Mpumelelo Nyembe. I have tried numerous times to call her but she is unavailable and promises to call and never does. This is purely disappointing and especially from such a big organisation. Why is it difficult to refund me the extra R5000 paid to my VAF account.