Expired baby formula

Bought a tin of baby formula from clicks brits yesterday as my 10 week old is strictly bottle fed. As I was about to prepare a bottle, I checked the expiry date on the tin as it was fairly rusted. And guess what? Formula expired. It's 20:00 at night where am I supposed to find a open store that sells nan AR and isn't your shopkeepers suppose to check these things atleast on a weekly basis? How am I suppose to explain to a 10 week old there is no formula to drink tonight. Worst part is, I threw away the till slip when I left the store as I thought you guys could be trusted when it comes to these things. Never shopping at clicks again.