No compensation for stale products!

Recently purchased two boxes of ProNutro cereal, open opening them, we found them to omit a stale odour and taste although still well within the sell by date. My wife duly reported the matter to Pioneer Foods, they came and collected the two said boxes and after a lengthy period of time responded accepting no responsibility for the stale taste and odour but rather suggested that they may have been stored incorrectly. No refund, no return of the products whatsoever, rather just passed the buck! I find this extremely unprofessional and annoying that a company of this magnitude did not even attempt to offer replacements or compensation of any sort.