[Hypersomnia]

Now the question is, what would happen if i used that method with a high value item?

It depends on the Item, your method and the representative handing your request. No SE Is guaranteed to work each and every time.

If you prepare, formulate and execute your method accordingly, the likely hood of a successful outcome significantly Increases- Irrespective of Item value.

I see, yes i totally agree.
Now to be more specific, what actions could amazon actually take in a scenario like that? The last very simple SE i did resulted in amazon just trusting my words, they apologized and sent me another item.
In short, almost no social engineering was involved in this case, only me pretending to be a slightly pissed off customer that just wanted the item he paid for.
What could amazon do in a situation like that if they don't trust me?