Referee didn't give Barça a penalty for the first minutes when the match started though, why don't you complain about it? referee has always been a part of the game, but foe me Barça did everything they could to take it and PSG even admitted and they never complained about referee. 
Barcelona is way better compared to PSG in every aspect, even when they lost 4-0 in the first match they still dominated from A to Z the match and yesterday it was the same scenario only Barcelona this time poured goals against them, but you can't blame the referee because the referee also didn't want to give Barça an obvious penalty at the first minutes that's why the referee is considered as part of the game nowadays, and let's face it PSG didn't play at all during whole match it was Barcelona and Barcelona over and over again me personally I hate such tactic of closing the game and defending with 11 in the field like for real? Barça deserves to be in the 1/4 unlike PSG yesterday, and they admitted that they suck and they even said that they have mental issues and it wasn't the referee who was against them like have you seen Neymar's free kick? that goal brought back everything and saved Barcelona's from disqualification 
Once again, it DOESN'T matter who dominates, they won dirty, be a man and accept it, and we move on. Barca can win games without any help, and that's how they should do it. Most of the times Barca dominates every single match, sometimes they happen to lose, I feel bad and angry, but it's football, it's not about possesion or who's better. They were stupid enough to lose the first game 4-0, so they couldn't turn it around by themselves. They were helped, that's how it is, and you know it. I really hope they win the ChL, but they don't need help to do so <3