Pathetic Returns Policy and Service

My dad visited Pro Visions bookstore on the 09/02/2018 at 2:30 pm, with the name , author and edition of the book that i had needed , the cashier had given us a different edition which costed us R780. She failed to mention the returns policy and didn't inform my dad to sign the receipt. On the 10/02/2018 i arrived at the store at 8: 30 am with the intention of exchanging the book for the one that i had needed, the manager refused to exchange it , saying that it is a second hand book and that the seller had already received a notification, within these few hours, the book is 6 years old. She insisted that her cashier had informed my dad about the returns policy at time of sale yet she wasn't present. She wanted to take the book back and attempt to sell it for me , i wouldn't have even got my R780 back because that is the profit mark up price and the students at UKZN are using a later edition. She then added that the students at Mancosa are using the book , and they would buy the book. I found it hard to believe that a reputable institution like Mancosa has not updated their educational resources since 6 years ago! , it just shows their incompetence when it comes to students and the resources that they need.