Unhappy customer

Unhappy customer On the 26 June 2021, telkom tried to debit my account legally but there was no money, its bounced back. I called telkom to make a payment arrangement, I told them I will have money on the 29 June 2021, they can debit my account. They told me that, they can't re debit my account, I must make a direct payment, they gave me their banking details. On the 29 June 2021 I paid them, a direct payment. 1st of July my account was debited with the same amount that means I paid them twice. I'm still waiting them to refund me but they haven't and they also charge me fee for a reverse debit order.

I need my money back and also interest because they are my debtors. Fine to debit my account after I paid them.