Cotton on Refund does not reflect on the RCS store card

This has happened in the past so I am frustrated as to why this is still an issue. I bought some items from Cotton on on the 30 October and returned a few of the items on the 3 November. The refund reflected on the Cotton on slip, however was not refunded by RCS onto my store card. Despite numerous emails and phone calls this has not reflected on my account. How do I get this sorted when no one will give me feedback??