Returning goods (slip) without ID or Truworths Card

Why is an ID or Truworths Card, is required when I return the child's shoes the next day with the slip only. Yet the store Manger Ezekiel Malungane can only say it is policy yet it is not mentioned on the back of the slip. Cant even explain any risk relating to return of goods with the slip Truworths JHB House. Yet my colleque returned a dress from Randfontein, same stance was pulled and yet they accepted the goods. LOL he gives me the same store telephone numbers for complains, and sound so proud about the issue.