Cross Trainer refusing to pay refund for order they failed to fulfill.

I have placed an online order on the 18 Dec 2023. On the 24 Dec 2024 I got an email that they cannot fullfill the order due to dirty stock and asked if I would want to replace or cancel the order for which I opted to Cancel.

On the 29 Dec 2023 they confirmed order cancellation and advised refund has not yet been processed.

I have been following up with them and until today my refund has not been paid.