Marks And Spencer — Refund not issues

I returned a pair of jeans on 17th nov 21 and have still bot received the refund of 1799. I have sent several emails and also written to the grievance officer for the company Kshitij chawla but there has been no response. The customer service agents are not helpful as they keep telling me that first we had not received the item and now we have received it but there is some technical issue and we will process the refund in 72 hrs. I don’t undewhich 72 hrs are they talking about because the refund never comes and there is nobody who knows what’s going on. The agents are ill mannered and badly trained they keep disconnecting calls and never call back even when they promise to. I have a complaint no 429523 but don’t know what the status is of the complaint as there is nobody who can tell me.