The Plovdiv-based club is angry with referee Stanislav Stavrov after claiming they had a goal wrongly disallowed as well as being denied a clear penalty that could have booked their place in the Bulgarian Cup final.
Bulgarian soccer fans have taken to social media to express their anger after Stavrov failed to award a penalty after Botev's Brazilian striker Joao Paulo was clumsily brought down in the box by Slavia defender Stefan Velkov in the 84th minute.
Two-times Bulgarian champions Botev lost 1-0 in the second leg in Sofia on Tuesday and were knocked out on the away goals rule. Slavia will face city rivals Levski in the final next month as the winners qualify for next season's Europa League.
Botev also called for the BFU's refereeing commission's chief Yordan Stalev resignation and demanded a life ban for Stavrov.
"The management of Botev Plovdiv expresses its huge disappointment and disgust from the way the semi-final clash in the Bulgarian Cup against Slavia had been vitiated," the club, who won the Cup three times, said in a statement.
(Reporting by Angel Krasimirov; Editing by Matthew Mpoke Bigg)
