What was stated in the box?!

On the box, it would state all the accessories included. If there's no mentioning of the sd card, then it's not included. Simple as that.

Even if the set is from DIGI, DIGI doesn't have the right to open up the packaging even to include one SD card into the phone.

Again, like I say; check the box. On the box itself there should be somewhere stated what accessories is included.
This is how one verifies whether the package had been tampered with.

For now I think it's better to close this topic.

However, after you've checked the box and found that it is really missing; then you may open this topic back. Then I guess no one can fault you on that.