Long life milk does not have a long life

I sent PNP an email but got no response. We brought a six pack long life milk at PnP Brackenfell Hyper in December. On Monday my husband opened one of the boxes of milk and it was a yellow clear colour but did not smell off. I poured some of it out and the sediment came loose. White chunks, also not smelling off but not usable. I do not understand what goes wrong in the process but it shouldn't happen as it is supposed to be long life milk. Please look into the quality of your products!