Barcelona say refereeing “errors” cost them a place in the semi-finals of the Champions League, and have caused “significant sporting and financial harm to the club”.
As a result, the Spanish giants have made a second complaint to Uefa about officiating across both legs of the tie.
Barca had a player sent off in each leg of their 3-2 aggregate defeat by Spanish rivals Atletico Madrid, with their 2-1 win on Tuesday not enough to overturn a 2-0 deficit from the first game.
In both cases, a yellow card was upgraded to a red after the referee was instructed to review at a pitchside monitor the possible denial of a goalscoring opportunity.
Pau Cubarsi was dismissed by Istvan Kovacs in the first leg, and fellow Barca defender Eric Garcia was sent off by Clement Turpin in the second.
Kovacs was also criticised by Barca after he and video assistant referee (VAR) Christian Dingert allowed play to continue when Atletico defender Marc Pubill handled the ball in his own penalty area.
Barca had already protested a “grave lack of VAR intervention” following the first leg, with Uefa deeming the club’s complaint “inadmissable”.
After filing a second complaint to Uefa, the club released a statement claiming that “several refereeing decisions were made that did not comply with the laws of the game”.
Barca accused officials of “incorrect application of the regulations” and criticised the lack of VAR intervention “in incidents of clear significance”.
The statement added that “the accumulation of these errors had a direct impact on the course of the matches and on the final outcome of the tie, causing significant sporting and financial harm to the club”.
Barcelona forward Raphinha, who missed each game through injury, told reporters after the second leg: “For me, this match was a robbery. Not just this match but the other one as well.”
A Barcelona statement added: “Through this complaint, the club reiterates the requests previously made to Uefa and, at the same time, offers to collaborate with the organisation with the aim of improving the refereeing system to ensure a more rigorous, fair and transparent application of the laws of the game.”