CAT FOOD MADE MY CAT SICK

Friskies cat food was discontinued and replaced by PAMPER - I bought a 2kg pack of Gourmet cat food and to my distress noticed that my cat everytime he ate this food he brought the meal up. Resulting in us taking him to the vet as I was extremely concerned - and he said that this is a 3rd cat he had seen who had the same symptoms.

I phoned Pamper to investigate and was basically told sorry they have a new formula and did not even bother to hear me out.

I have since 2009 bought Friskies as this is the only cat food he likes.

Where and how what do I do?