slow to refund

I ordered an office chair online on 05/09/2023from Makro but canceled the order the same day unfortunatelyI canceled othe orderafter I paid for the order. and then canceled the order. I received a notification that the order was canceled but low and behold I received an email 2 days later on 07/09/2023stating that my order has been dispatched. I contacted their support via email. explaining the whole situation. I even contacted the courier company to tell them that the order was canceled and that they should return the order to Makro. he goods were returned to Makro. to date 18/09/2023 I am still waiting for my refund everytime I contact them they say that they escalating the matter, I think they use ***eon service to escalate matters. all I want is for my money to be refunded. I am a 60 year old on Government pension. why is it so difficult for them to process the refund?