[mothered]

If the company come back & say the parcel was signed for and the tracking shows it has been delivered to my address, how do I even reply to that?

It doesn't mean "you" signed for It, hence didn't receive It. I've experienced so many Instances, whereby the "driver" signed for the package due to being In a rush. Throw this at them and they can't deny It.

If It's not your very own authorizing signature (random scribble), you're not held accountable for receiving the package. It could've been a passerby who accepted and signed for It.

What if the driver specifically remembers coming to my door and me signing it?

Firstly, drivers deliver so many packages on a daily basis, so he won't remember some random delivery that's of absolute no Importance to him. And If he does remember, word-of-mouth Is not enough to justify a delivery.

Do drivers get penalized/fired when that instance arises?
I mean, if the package figures as "lost in transit" because you scribbled a fake signature and then claim that you didn't receive the item.

It's not possible to speak on how each and every company Is structured, and the handling of their Internal affairs.

I'd say a warning at the minimum will be given.