Wrong Size Delivered

On the 14th of December ordered a pair of shoes ,wore it ,threw the box away,noticed later the shoe is big,I ordered Size 5,5 and Recieved SIze 39 i didnt know that 39 is size 6,i phoned them now to enquire about a return told them i dont have the box anymore was told that the shoe cannot be returned without the box,I was assisted by a lady called Phumeza who refused to give her surname claiming that the people are getting killed out there she cannot give our her surname. Im very dissapointed all i want is a right size ,i cannot buy an expensive shoe and be told i cannot exhange it because of the box.