i bought the 4-pack RPG maker Vx Ace on that shop: https://ssl.dispenser.tf/trade/151441/
time: january 5 at 11:54
I got the gift after sometime.When i used the gift from my steam inventory, i only got 1 copie on my library. I was suppose to get 3 copies in my inventory but i have nothing.
I can't add the seller it seem like he blocked me....
When i look his inventory, i see 3 gifts of the game...
i want to understand

The gift has "4-Pack Gifts" in description which means it is a single gift that came out of a 4-Pack split. Whenever you see "Gift" in description it means it is a single gift, not a whole pack. A whole 4-Pack would not have "Gift" in description.

So to make it simple:

RPG Maker 4-Pack --> This is a whole 4-Pack.
RPG Maker 4-Pack Gifts --> This is a single gift copy that came out of a 4-Pack split.

This is not the seller's fault unless he advertised it as a whole 4-Pack, in that case you should contact him for a refund.