Non existent customer service - client suffers loss for their tardiness

I do not even want to give them a ‘1’ as there was no service to speak of. I ordered 8 items and returned them all (using their return service provided). They have only refunded my account for 5 of the 8 items I sent with the courier and still owe me a refund balance of R4399-85. Over the period of close on a month, I have spoken to 5 of their call centre agents, emailed on numerous occasions, asked for the situation to be escalated with absolutely no actions or accountability. There is not even any kind of apology or justification for such pathetic service. I will continue to fight but extremely unfair and unnecessary.