I've been dealing with a customer for a few days - she placed a large order (for my shop) of 7 items for $450. I fulfilled it, shipped it USPS with tracking, and it was marked delivered last Thursday. She immediately messaged me saying it did not arrive, so I did a lot of back and forth about "waiting a day or two" "check with roommates, neighbors or your apartment office" and "check with USPS about the GPS as to where it was delivered" and finally gave her the option of submitting a police report (which if she actually did I may re-make her items).
My profit on the order was about $130, so to refund like she asks would be a loss of $320 which I'm not willing to do when tracking says delivered.
She hasn't given me much information about the steps she took but just said "no one will help" and "I give up" and then proceeded to give me 7 1-star reviews. I know I can report them but they likely won't be removed, and this is going to absolutely tank the algorithm for my shop. Any advice?