nearly a month ago

i bought a pack of muesli and found a lump of oats with mildew.i send pics,the till slip,the packaging. their not responding in a manner that show they wont to address the serious health risk that this old stuff posses.I have an up set stomach because of not realizing that muesli were filled with mildew.the operation manager has not did not return my call as i asked him as it was not possible to speak to him.They treat this matter very nonchalant.