Builders Warehouse owes me over R600 for items not delivered and various refunds.

I have been emailing back and forth with an agent at Builders Warehouse since 12 March about refunds for various items not delivered in my deliveries totally over R600. I keep having to send my proof of payment, and then people phone and email me saying the refund has been made, but there is no evidence in my bank nor on my profile online as a credit.

Someone needs to assist me with this as it is tantamount to ******* to just ignore me when you own me money.