USPS, not so much. On a recent order from Barlow's I got size 4 treble hooks instead of the size 2 that I ordered. I contacted them and they sent out the size 2 hooks without any charge. Great. Then yesterday USPS tracking showed package delivered to mailbox. I don't know who's mailbox, but it was not in mine. Notified USPS, still waiting to hear. I still need the size 2 hooks, so I placed a new order with Barlow's for the hooks and other items. About 30 minutes later I get a call from Barlow's asking about the hooks. I explained THE USPS malfunction and he laughed and said "I'm not gonna charge you for the hooks and I will expedite this order".
Now that's taking care of customers.