Something is very fishy here. I've worked in warehouse shipping and receiving, was an assistant manager for a cafe, and spent most of my years in manufacturing, signing for materials deliveries worth thousands of dollars and shipping finished product worth hundreds of thousands.

So, here's what's wrong. If you didn't receive (sign for) the product, somebody else did. When they received it, it's their responsibility to pull the packing slip to identify what's inside that package, check it's condition before signing for it, and then to take whatever steps are expected to insure the product is properly stored. This could be informing whomever is responsible for warehousing, or simply doing it themselves.

You did not receive that product. You were not tasked with the duty to store that product. You were not informed of the contents of the package. You did nothing wrong because you were not responsible for that product. Thus, you are being taken advantage of and being penalized for somebody else's negligence.

I suggest you contact your regional employee/workers standards office and enquire about your rights in this situation. Be sure to give every detail of what happened, what was said, and the result.

If they believe you have a case, ask for advice on the best way to deal with your employer in an effort to avoid filing a formal complaint.

If the situation cannot be settled between your employer and yourself, file a formal complaint. They cannot fire you for doing this, but begin looking for another job because they will make your life miserable. At least you won't be paying for $600 worth of rotten cheese, and you may be compensated for the hours you've unjustly lost.