poor quality

I bought 6 packs of long-life milk at Woolworths, but the quality was poor, and the milk was watery, I could not use the milk for anything, and then I called customer care the gentleman helped me nicely, then I got a reply via email that they did not find any problem on their retention sample so they will send me R50 voucher, which I find I unfair cos their milk is R95 and I could not use any of the milk plus my traveling expenses by the time I reach the shop R5 will be finished I was expecting one on one compensation at least .disappointed and I only buy Woolworths milk