Refund Issue

Poor Customer Service, ongoing issue with processing of online payment refund. Since 30 May till date. I have spoken to different people via email,telephone and whatsapp but nobody seems to get my problem solved. They keep coming back and saying the payment was processed on certain date could I please provide bank statement to show that I have not received the finds, this has the back and forth I have been going through since May, having to send my statement over and over again with no resolution.