If you complaint to UPS they put you on a do not deliver list and you will never receive another package unless you are standing in the door when they arrive. They will not tell you how to get off the list, and usually will not even tell you you are on the list.
But if you pay extra money, they will deliver to their UPS stores. This is to generate extra income for packages they already collected delivery charges from the shipper.
It is an obvious scam to make more money. Never use UPS, try the post office or FedEx to get good deliveries.