Clicks Customer Care - do they care?

I bought 6 bottles of Clicks Effervescent Granules instead of the Citro Soda and Alka Fizz that I normally buy. They claim to be lemon-flavoured and have exactly the same specs as the other products. They granules hardly 'effervesced' at all and there's virtually no lemon taste. To I emailed customer care, asking whether this was correct, or perhaps if this was a poor batch. I emailed them on 17 July, and again on 26 July, because they hadn't troubled to reply. The response "Please take the unit to the closest store for assistance." Clearly they had not read my email and this is a stock response - the 'unit'. The problem is that I didn't get an answer and, if I take the bottles back, I'm sure they will just refund or replace, so if the product is 'faulty', it won't be fixed. This is not what I expect from a 'reputable' pharmacy. I'm very disappointed.