Clarks — Missing Refund

I purchased the a pair of boots from Clarks online on 11/18/22. They arrived shortly after and were too large. I sent them back following Clarks instructions and placed an order for a 1/2 size down on 11/27/22. I have still not received a refund from the return even after spending hours on the phone over 5 calls to customer service. I would like a full refund issued for the boots I sent back.
Order Details:
1) No.[protected], 11/18/22, $142.43
2) No.[protected], 11/27/22, $113.94