Double Cream yogurt is not as thick as it used to be

I have been buying Woolworths Double Cream Plain yoghurt for a number of years and have been happy with the product. Something has gone wrong now: I have bought 4 1kg tubs in the last few weeks and the consistency in everyone of them is no longer the thick, stodgy yogurt I always enjoyed. The double cream is just as runny now as the normal Full Cream plain yogurt! Considering one pays a premium for the Double Cream this is very disappointing. Come on Woolies, do something about your QC!