Odd tasting coke zero

Bought 3x 1l bottles of coke zero a week or two ago. First 2 tasted like those chalky pink sweets and we didn't consume it fearing it may be contaminated with cleaning chemicals. 3rd one opened tonight tastes like iron brew....concerning since I can't consume sugar but glad its not chemical. Really disappointing when you pour a drink with coke and get SOMETHING else than what you bought.

P3 13:26 only marking on neck and BB is only 18/05/2018. Kept it in case you want to test or collect it.