MAKRO makes it impossible to cancel order and get a refund.

Makro make it impossible to cancel order and get a refund. One of the items on Makro order MAK*** is the wrong size. I asked the call centre if i can change the size. They said no: we need to cancel. I've called 3 times in two days to cancel. But Makro insist on dispatching the item. I just want a refund and the item returned to the seller. No one seems to know why it's so difficult to cancel and refund. Incompetence.