my dad's company is trying to get sued or asked to pay for the food that my dad canceled,

I already sent you a letter requesting for cooperation.
On 9/20/07 I prepared packed lunches for your company (for about
40 persons) under the implied contract. However, your company
cancelled the order 45 minutes before packing unconditionally without
any reason.
I can not help but to point out, as an example, you did not show exemplary behavior in the town as you ordered through another restaurant and violated general practices and customs of society.
I hereby request you to pay me $820 for the loss caused by item 2 above. This covers the food cost (prepared but unable to deliver), the Korean food material that could not be used elsewhere and the labor cost which was unnecessarily paid out.

is it unlawful?