they over charged me i pay twice for the liver tub

No name cashier charged me twice for liver tub I only bought one and I don't understand why she charge me twice because it was one tub why she scan twice I only saw a till slip on the morning and am so angry because I have to fone them waist my airtime and the lady who answer a fine she was rude I need my money back they must call me today and they must watch they camera invoice number it C0037 #0010 15:24:39 060615 S040989 R03 they must call me urgently on ***