Bokomo / Pioneer Foods foul smelling Pronutro

I bought a box of Original Pronutro from a well known retail outlet. When I opened the box for consumption (about 3-4 weeks after the purchase) it was smelling and tasting foul - although it was still a month before the expiry date. As I had not the till slip any more I realized it will be futile to try and take it up with the retail store. So I took it up with Bokomo that is operating under Pioneer Foods. I received a response email telling me it was escalated to higher authority. Eventually I received a letter from the higher authority requesting for photo's of the box, the expiry date and the till slip which I sent except for the till slip as I don't keep it for that long. Nothing happened. I forward my last email and photo's thinking that it got caught up in the junkmail box. I sent another email later also no response. So I contacted them again through their web contact option. Hooray, they responded with a letter just to tell me how sorry they are about my experience and that I must know that they take quality and satisfaction very seriously. Nothing more, nothing less. I rep**** to the sender asking if I should expect any further action. It is now about a month ago and still no response. So, I really wonder how serious are they about quality and satisfaction? I do believe now that it is definitely not high on the priority list. I previous situations with other companies the reaction and action was overwhelming positive and replacements was offered and sent faster than lighting could strike. Have companies become to big and to proud today to walk the extra mile. To sincerely step up services and replace foul and or spoiled products? (O yes, I do realize that there are opportunistic people - but should we all be treated as one...?)