Complain about phone

I bought phone at Mr price mobile samtuli mall on the 18th this month of November. This brand new phone when l switch on it jams then does not switch on,because l liked the phone l took it back for my refund so that l can look from other shops,now Mr price want to fix it a brand new phone, im very very disappointed of this shop,how can fix brand new device,l just want my money back will buy elsewhere. Im very upset.