Double charge for 1 item that was R17,15 instead I paid R34.30

Yesterday at 7pm I went to the store bought, 1,5 sparkling water R14.99, 1 sprite R10 1boxer queens cake R27.99, bananas, R17,15 but the bananas was scanned twice to my surprise I wondered y but the cashier name Masego Mphuloane over charged me yet her counter items were placed there ukuthi y did she make me pay double for bananas I paid R34.30. I am very disappointed cause I only noticed when I was out of the store guys your services socks worse I paid twice for an Item please make means to refund me I can't move from where I am for being double charged imagine the nerve my total price R87.27 your service sucks