NO Refund/CPA protection Section 55

My father bought a laptop on Friday at Maponya CNA and the sales agent did not explain anything but process the sale. When he returned home I advised him that the laptop is not a good quality laptop. To my dis-belief the laptop was opened and they had set it up for him (That is not part of the service). On Saturday morning I went with him and attempted to return the unit only to be told they won't accept the unit . The invoice states clearly that they do accept the unit with original package and receipt. They informed us that they are not allowed. According to the CPA I have every right to a refund and this happened within 24 hours. I do not know who said they need to process for us but I need a refund and for that cheap brand to be taken back as I do not understand why CNA would be selling that Laptop to begin with.