bad service they don’t want to refund me

i have mistakenly paid an amount of R39922.77 into makro credit account i write an email to them sending proof of payment but they still run around and taking long to refund me it’s been two weeks now they even ask me to send the a detailed slip i send them a bank statement that indicate everything is like they want to keep my money even when it’s reflecting into their account i keep on phoning them they tell me refund department will respond i mean proof of payment and bank statement is enough i need to use my money .