Chemical taste in yoghurt - still no feedback

I posted a complaint on the 28 September regarding a chemical taste in my yogurt i did receive a call asking for the batch number etc. I did ask for feedback after their investigation as to what chemical was in the product as we did eat some and we gave it to our kids. I am still awaiting feedback. Very disappointed as it will be 1 month in few days and i am wondering if they even did an investigation. Also i was told I would receive some vouchers as I had bought 3 trays of these but still nothing.