Not treating customer fairly

On the 25/11/2020 they have over debited my account. On the 26/11/2020 I let the company know and requested a refund via the chat. The consultant who assisted me by the name Malebo, told me that my refund query has been escalated. I the asked what is the turn around time, she responded by saying the system is offline on the day and payments are processed manually. I then said hopefully it will be sorted by the following day 27/11/2020. After that I received no further communication about the refund. On the 28/11/2020 I do a follow-up and to my surprise I'm told that I must submit a bank statement so that they can check if there was no dispute. How are you guys treating customers fairly? Now I must be inconvenienced and incur the cost of bank charges for the bank statement and I must be delayed to receive what is due to me. And if I didn't follow up,when were you planning to tell me? Please stop acting like ****** and process my refund like you didn't have a problem to deduct money from mt account. I don't owe you anything, you guys owe me.