I just feel robbed..

I bought 2 times 900 Souls and one other time 390 I used all the Souls at the Shop and i didn't win a únic item!!! This is like robery... I feel robbed...

I've done the same payment of yours and got only a shitty Thunder Helm. Then i read about unique drop on inferno stage And with infinite stamina i dropped 3 inferno items and tons of stones in a week!

What lvl i must have when i can drop set item?

You can be any level to get the item from the store, for a drop I'm not sure but I'd guess at least 50. My first unique didn't drop till I was near 100. Good luck.

I wanna up to 70 lvl without using soul and at 70 lvl but item tier 15 and unlimitet stamina.

What do you think about this?

What inferno? The first one? Or the second one? And what stage?

Well, that is chalanging, but in that Way you lvl up much faster then normal, unlimited Stamina is very usefull