Chicken that was off

I bought chicken thighs and chicken fillets from pick n pay on the 30th of November, the expiry date on the chicken was for the 4th of December. I wanted to cook the chicken the next day (1 December) and it smelt like rotten eggs! Both packets of chicken were rotten! This chicken was off when we bought it!! This is not the first time this has happened to me from pick n pay...! I am very annoyed! Would rather shop else where then.