The customer placed an order 2nd week of July. Tracking says they got it on the 14th. They are saying they did not get it and now they want a refund. How do I handle this situation?
You or the buyer need to call their post office to have them look up the GPS where delivered.
I've said this hundreds of times and it bears repeating:
Just because tracking says it was delivered DOES NOT MEAN it was ACTUALLY delivered NOR DOES IT MEAN it was delivered to the right address/person.
Call the customer's Post Office and get the GPS tracking details. Don't make the customer do it - it's good customer service to do it and then you also know the truth.
Their local post office should be able to check the GPS and tell them where the package was delivered. If the tracking says delivered you have fulfilled your part of the contract. Anything could happen once the package was delivered; it is the buyer's responsibility to provide a safe place for mail delivery. It's overstepping your boundaries to try and track down your buyers missing mail.
I happen to be all for the seller being the one to contact the post office. They can verify actual status and delivery location.
It's also possible that it was a victim of porch pirates or falling out of the mailbox or off the porch. Once it turned out that the husband had squirreled a package away (it was packaged in a golf ball box) because he assumed it was for him.