Be very weary of LeroyMerlin online

I ordered an office chair online; the product was faulty. I have been trying to get it collected so I can get my refund for over 3 weeks. No one from LEROY MERLIN helps (Ref Conny Ratau - *** as well as ***) nor from CALASCA (Ref Avi Chetty Avi ***). They send repeat emails that they are aware of the query but no one has done anything tangible to resolve the matter. I was promised an immediate refund by *** on 21 June which I accepted but to date, nothing has happened. My order number is ***-A.