Refuse to refund the payment i did on the 30-04-2024

I paid the subscription on the 30-04-2024. and on the 1st May-2024 they withdraw the subscription payment from my bank. It was double the payment they receive. I lodge a refund requisition with them, i send them the document with banking details of the transaction i did online on my bank app. Today i receive a call from a consultant that they need my banking statement. I ask the consultant that why they need my banking statement, as i was not applying for credit from them, I was only asking for a refund. the consultant didn't answer my question, she just told me that i won't get payment because i didn't submit the statement. But I submitted the banking transaction details that i receive from online app from my Nedbank that happened on the 30-04-2024 which is the same thing that is on the statement. They refuse to refund my money base on the statement.