Thats after 12 years of Iranian regime funding Hamas with billions of dollars. Once Hamas saw Assad is losing they kicked his bum. But then when they saw Assad is winning again they came back to continue suck Iranian billions.
Sanctions are also result of the support of terror groups and wars outside of Iran.
So basically its double hit:
1) They take billions from poor Iranians to slaughter poor Syrians, Yemenis, Israelis.
2) And as result they get only sanctions, which hit Iranian poor even more.
Meanwhile regime functionaries having fun: