Is this a new scam? Tracking # piggy backing

I ordered an AGM battery online (should have researched the company better). Anyway @ a week later tracking shows it was delivered. But it wasn't delivered. Called FedEx & they said it was delivered, I said not here it wasn't. We were here that day. They asked my address, then said that isn't the address it was delivered to, same town, different street. They would not give me the address because of confidential reasons & I definitely understand that. I emailed the company,  waited a day then filed a PayPal case. The shipper provided the shipping delivery to PayPal & they denied my case & closed it. At this point I was really mad & finally found a PayPal phone # so I called & talked to a real person. 
The PayPal rep listened to my story & apologized, then said he would just call FedEx. After only a few minutes, he got back with me & said it was the wrong address & credited my account. He said it probably was never even shipped & most likely a shipping piggy back scam & his account will be closed, they will investigate any other accounts he is associated with & probably be charged with crimes if it's more widespread.  
My question is how would someone get a shipping # going to my town & change the weight so it looks legitimate? Would it have to be someone with inside shipping company access?  I've received hundreds of packages & have never seen this. Had things lost & stolen by USPS, but never issues with FedEx or UPS. 

My thought is they ship dead weight to a made up address in your town.  They have the money for the battery just out the bit for the shipping.  Actually kinda smart of them.  Probably get away with it 9 out of 10 times.

In reply to Stampie :

That's what I thought initially until the PayPal rep called it piggy backing. Oh well I got my $ back. 
 

In reply to mdshaw :

Oh maybe they scan tracking numbers looking for a matching town one.  I could see that happening with a quick script because all the shipping companies have open APIs that'll let a non human track E36 M3.

This happened to me once.  I ordered a mattress on Amazon.  While I was at work I got a notification that it was delivered.... by USPS.... and it was left in my mailbox.

I wasn't shocked when I didn't find a mattress in my mailbox, but I called USPS to ask about it.  They looked up the tracking and said it was a 1.7 lb large envelope delivered to a street a few blocks over.  I put in for an Amazon refund and got it, so I went back to order another mattress only to find that the mattress, the seller, and everything about the seller was gone.

I assumed that it was a fake seller who collects money then ships an envelope or a flat rate box somewhere with a tracking number just so they have a number to give you.  By the time your "mattress" gets delivered, they've collected their money.  My guess was that they use a very similar address in your zip code so that humans glancing at the envelope don't think twice about the scan/track not matching the address written on the package.

Had the same thing happen from something heavy from china , 

got the tracking number and checked the USPS website to find out that the 25 pound package was 14 oz  , 

got in contact with Paypal  and got a full refund .......and I never got the 14 oz package !

you wonder if some of the overseas scammers are working with a buddy at the local post office .