Old Baby milk formula

I bought formula from woolworths on Monday the 9th of November and opened it today it smelt so bad so I checked the expiry date only to find that it expired on the 05/2015 almost 6 months ago....I took it back and all woolworths could say it's not there fault and gave me a refund I am so disgusted at the lack of sensitivity they had because if I had to give that to my baby would they have paid for his medical bills as it would have definitely made him sick.