Fnb refuses to refund my money.

Fnb ran a second debit on my account, after I had manually paid for my insurance. I sent a proof of payment and they acknowledged a payment and told me they'd refund within 7 business days. This was on the 17th of September 2025 when I spoke to Namhla, Aldrid, Palesa, Asanda and Lesego about the double payment, it's the 28th today and they still haven't refunded my money. I paid manual on the 12th, on the 15th they ran another debit, on the 17th I contacted them. But I'm still waiting for my refund. Why must I wait so long for my money?