Unauthorised debit order amount

Disgusting service from Miway as I was debited an extra R775.00 on my insurance premium this month. I've been waiting since the 1st of May for feedback and was told that I need to send bank statements to show that the debit was successful. During a lockdown due to a pandemic I must stand in a queue at the bank because you can't do something as simple as debit the correct amount? As I stated I want the refund with immediate effect. You're very quick to take money that isn't yours but I must wait DAYS for you return it