ROTTEN MEAT!!!

I am SO tired of buying meat which is off!!!! On Tuesday I bought a pork pack which was labelled sell by 20 November...tomorrow...when I opened it last night to make dinner....it was off...smelled disgusting...this happens on a regular basis. I don't have money to throw away like that. .and to have to keep taking things back...I had to get takeaway because I had nothing else to cook...waste of more hard earned money....I'm totally fed up...nothing seems to be done and one is told... just bring it back you can get a refund or take something else...at 6pm I have no desire to be running around for food I had planned and bought in good time....exasperation doesn't even come close to describing it