Coke taste like cheap cola or completely flat

I purchased the 4x2L Coke from checkers hyper at Nortcliffe corner in JHB and every bottle opened taste like either cheap cola or flat coke more like cheap cola that was put into the coke 2lt and sold as coke.<br> barcode : ***8688 BB 27 MAY 2016 16AE3 05:50 Jc. THERE IS DEFINITELY SOMETHING WRONG WITH IT SO I WOULD LIEK FOR IT TO BE TESTED TO CONFIRM WHAT IS THIS IN THE COKE BOTTLE AS WE ARE PAYING OUR PRICE FOR COKE AND NOT CHEAP COLA.