Spoilt chicken

I bought marinated chicken from shoprite and as i was driving home there was this awful scent in the car that i couldn't figure out where it came from...I even thought that maybe i had bad breath since I've been wearing a mask all day. As soon as i got home and was unpacking my groceries there it was, Rotten marinated chicken one of the pieces had even adopted a blackish colour. What amazed me was that my mom was not surprised she told me that it's their common practise to use marinate and spices to cover up rotten raw meat. I'm so disappointed.