You Must Be Joking

The computer and monitor spectacle has taken a new turn, a turn for the worst, a turn that takes this into unbelievable!
I sent the computer seller an email on Sunday saying it's been a week since they told me a replacement would be sent on Monday and I would really like some action on their part or a refund.
Today I got an email from them saying they had shipped the computer and monitor and, according to their information, it was delivered last Thursday. So, I took the tracking number they gave me and went to the UPS tracking site. Yep, according to UPS they did deliver the packages last Thursday.
Here is where it turns absurd. I sit at home all day every day using this computer. My view is through the window beside the table that looks directly towards the front door. I can see if someone comes knocking at that door. Now, according to UPS they delivered the packages and left them on the porch!
So basically what they are saying is that in spite of the fact that they are delivering over 20 pounds of goods in 2 boxes they just left it sitting on a porch somewhere, no signature required, no nothing, just leave the boxes and continue on their route???
I call the Customer Service man at the computer company to explain the situation. He is confused as I am as to why they would just leave the boxes on a porch. Now the next step is that he passes it along to a manager and that manager will contact UPS and launch an investigation into where the boxes actually were delivered, by whom and whatever else they deem appropriate. I hope he gives them a good butt chewing for being so stupid!
Ironic, Shelly told me before I ordered the computer and monitor for her that she was in no hurry, she could wait until December for a new one. At the rate things are going, she may just get it by then.