Refund not paid as promised by Metrofibre

I mistakenly made a payment of R5030 on the 14th of March and when I ask metrofibre to refund me ,they said that to process a refund takes 30 working days.i pleaded them with the company that I had bounced debit orders and I am kindly requesting they prioritize the refund and after alot of hustle. They told me that the refund was approved on the 18th March 2025 and the money would be in my account by the last Friday of this month.Today is the last Friday of March and the money is still not yet in and I tried to contact them and they said the finance department will reply me via email.i sent the finance department an email and they did not respond,I would like to understand why does it have to take 30 days to process the money that they received the same day .This policy of 30 working days is just too much because it's money that belongs to me and I have given them all the documents they required from me to process this refund.