Insectsinside food parcel

purchased a pocket of knorr pasta souce, smoked ham ans cheese flavour and the expiry date was 20 july 2016 but when I used it it seemed to have tiny black bits that looked like they had tiny feet and when I looked closely saw that they really DID HAVE FEET AND THEY INFACT WERE INSECTS. How can this b? Hade to throw my pasta away....