Pathetic service by DPD and Cape Union Mart

I have received pathetic service from the DPD couriers (Heidelberg) and Cape Union Mart. Returns for three Cape Union Mart purchases were scheduled on 16/05/2023 and collected by DPD Laser on 17/05/2023. By 27/05/2023 I have not received any feedback or any refunds so I've sent an email to Cape Union Mart who hasn't responded yet. A follow up email was sent on 02/06/2023 but still no feedback. I contacted the courier on 02/06/2023 and it was found that the three parcels were lost. I have followed up several times. At this point in time. I have been informed that Cape Union Mart has received one of the parcels but two are still missing. I was promised by the couriers that Cape Union Mart will refund me, but nothing has been done yet. I have phoned Cape Union Mart and also complained on their Facebook site but the problem has not been resolved yet. Please assist and refund my money.