Adcom Mobile - Delivery boy not pick up return things He did not make a call to the customer before he came

I ordered a phone to my customer but it is not working so requested to return the courier boy was came and he made call to the customer but at that time my customer not available, her children pick up the call. After a few minutes my customer made phone to the courier boy but he did not respond well he told her that he can not come again to pick up the product. My customer dissappointed. Please meeshow solve problem. Courier men not working well. They are very lazy. Finally he shows calls list.He is very cunning. How can he did Iike this