Off Wine/Taste like Vinegar

I am a loyal customer of Robertsons, we buy at least 4 of your 3L Merlot box wine per week. <br> <br> Over the past year, there has been many boxes that we have purchased that just taste awful. <br> <br> Normally I return to my supplier and they replace, but this week alone now 2 boxes already.<br> <br> I don't understand how can your wine go off like that? <br> <br> The info on the Boxes that I have are both the same, FILL DATE: 12/12/2014, L49140 Vintage 2014 (4).<br> <br> I am utterly disgusted with this, I mean we buy a 3Liter for R125.00 per box after the sin tax went up in Feb.<br> <br> My supplier tells me he has complained himself send you guys mails and nothing.<br> <br> Surely for a winery of your standards you would go the extra mile for your consumers.<br> <br> Hopefully your PR or Marketing department will pick up the pace getting back to consumers, and wherever you box your wine do much better quality control.<br> <br> <br> I love the wine when it tastes like a proper Merlot not like vinegar. <br>