Why must i always nag and dig for standard service

Went to the store today to return the book I personally purchase on the 8 February 2016. Was attended by a young beautiful lady whom ask for authorisation from Chevron and she declined. The lady whom was helping me ask other staff member whom I don't know her name as each and every staff member was never wearing name budges. She came and authorised the transaction Chevron once again came and said my card is not allowing the vanschaik system to refund money into my account. She then went to the back and said they are unable to refund me as the book was given to me sealed, they claimed. Told her that the book I purchase to them was never given to me sealed. She said I need to speak with the gentleman at the intonation. The gentleman also insisted that the all Unisa textbooks enter the store with seal, he said he found it very strange that only mine came unseal. And he also refused to refund me my funds. I personally ask the guy to review the surveillance cameras and I am so much disappointed because due to my race I was treated unfairly as a paying fully South African. This is an second incident. Bad bad bad service.