Should I file a police statement against delivery company?

As long as you are filing a police report in good faith, based on what you believe to be true, there is no harm in filing one. It is possible that the police will investigate and, if they do, that may help you get your washer back.
However, while there is no harm in filing a report in good faith, be aware that there is a significant likelihood that doing so will not in fact accomplish anything. First, there is high probability that the police will not take action, based either on a belief that this is a "civil" matter involving a breach of contract or dispute between customer and store, not a crime, and so should be resolved via lawsuit; or even if they think it may represent a criminal act, many police departments will simply not devote resources to a matter like this, not when they have drug and violent crimes to deal with. Second, even if they take some action (e.g. investigate), that is no guaranty they will find the washer or determine what happened to it.
Remember also that it is only a crime IF someone deliberately took the washer; if it was lost by mistake, that is not a crime, though it is still something you can sue over (see below).
You can sue for the value of the washer, if you believe the store or its employees lost it, broke it, disposed of it, sold or gave to someone else. Proof of a criminal intention is not required for a civil lawsuit. However, you can only recover the actual value of the old washer *at that time* given its make, model, age, condition, etc. Unless that is considerably more than the amount of money you are being offered, it is likely best to simply accept the offered compensation and move on.