Postal Insurance Is Not A Sure Thing....
Just a heads up about insuring things through USPS. I have been selling/buying on Etsy and eBay for a long time and ship lots of stuff.
Insurance doesn't guarantee you will get anything back should the package not turn up. I learned this the hard way.
You need an actual receipt showing what you paid for the item. NO receipt....your claim is denied. If the Post Office determines that the item(s) weren't properly packaged...they deny your claim. That can be subjective and totally their call.
If it is something "liquid"...like alot of the stuff swapped here and you don't state that it is "liquid"....you guessed it, claim denied.
IMO....as a seller it is my responsibility to ensure the buyer gets the items they bought. If the Post Office messes it up....I refund. This is not the buyers/swappers fault. Your beef is with the Post Office.