To have bought one rancid chicken is unfortunate, to have bought three sounds like foolishness. Why did you not take the original chicken back to the store? Why did you not alert the environmental health department with the second? Why on earth did you contemplate buying a third from there?
Asda have very robust processes to ensure the food they sell is stored correctly and having alerted a manager, you have done all you can.
Incidentally, I haven’t heard of an outbreak of food poisoning in Wrexham brought about by Asda selling rancid chicken.