Is it the same to “unlock” that to “unblock”?

Not usually. By “unlock” you usually refer to “SIM unlock”. By “unblock” you usually refer to “blacklist unblock” or to “iCloud unblock”. SIM unlocking your device has nothing to do with unblocking or not unblocking. You might have an unlocked device that it blocked… that will be of no help. Please, do not submit “blocked” devices, because there is no refund if they are “unlocked”.