Expired products

I went to Usave in Braamfontein (Smit & Simmonds Street) earlier this year. I bought snacks, sanitary pads and milk. To my surprise those products were expired. Yes, i might have been wrong for not checking the expiring date but why would a food retailer put expired products on the shelf? futhermore, that U-Save is dirty & some products do not have a price tag.