Cape Verde said the refereeing was not fair during Saturday's 2-0 loss to Ghana in an Africa Cup of Nations quarter-final.
The islanders' coach Lucio Antunes and his players said referee Rajinjapasad Seechurn from Mauritius should have awarded them a penalty in the second half.
"This was our fourth game and in our first three games, there were no questions -- now there are questions. You should draw your own conclusions," said a disappointed Antunes.
"They (the organisers) would want to see Ghana move into the semi-finals or do you want 200 spectators to watch Cape Verde against Togo in the semi-finals?"
"There was a penalty when Djaniny was fouled, but the referee did not give it to us," said defender Fernando Varela.
Cape Verde reserve defender Guy Ramos said: "We have serious misgivings about the referee in today's game. Ghana were lucky with the calls by the referee."
Ghana skipper Asamoah Gyan maintained the penalty awarded to his team was a correct decision after he was brought down nine minutes after half-time.
Substitute Mubarak Wakaso converted the kick and added a second on the break five minutes into stoppage time.
"It was a penalty. I was ahead of the defender and he took me down from behind. I respect the referee's decision," Gyan said.