Illinois delegates elected to represent Donald Trump have voiced fears about chaotic organisation and a lack of leadership in their state as Republicans prepare for what could be the first contested convention in decades.

During a torturous two-hour conference call on Thursday night, the delegates struggled to figure out how to help the frontrunner at the Republican National Convention in July, wondering how best to contact the campaign in Wisconsin for tips.

Anxiety was mounting throughout the conference call about the lack of organization in the Land of Lincoln for Trump. As one person said “There is no Trump team in Illinois, it’s us”, a statement echoed by pro-Trump activist Doug Ibendahl when he pointed out on the call “we don’t have any leader, it’s just us.”

The Guardian understands the delegates also tried to deal with the mysterious disappearance of former Trump state chair Kent Gray from the campaign’s operations. Before leaving the campaign, Gray had tried to keep rival campaigns from making the ballot in Illinois but failed because he had not filed the paperwork in a timely manner.

They also spoke about fears the #nevertrump movement would use “riffraff” to steal delegates and were uncertain about what to do next to help secure the GOP nomination for Trump.

In the state’s primary election on 15 March, Trump won 39% of the vote and 53 of the state’s 69 delegates to the convention.

There were a lot of questions about what the infrastructure in Illinois would be in a general election for the real estate mogul in the state and what type of organization was there in the state. As people on the call noted, Bill Graff – the replacement for Gray – was a volunteer who was seemingly dragooned into taking a leadership role by the national Trump campaign. Many of those on the calls were Trump loyalists, including one ready to move to a new country if Trump didn’t win.

Callers also spent time mourning that Pat Brady, former Illinois state GOP chair, won a delegate slot because of anti-Muslim prejudice among Trump voters. What was imagined to be an effort to mount a diverse slate of Trump delegates led to several candidates for Trump delegates with “Muslim-sounding names”. They underperformed in Illinois’ complex primary election because of what one caller described as many “people avoiding the guy with the Muslim-sounding name”. As a result, Brady, a Kasich supporter, “snuck in”.

Trump’s campaign is trying to ensure that the bombastic billionaire gets the 1,237 delegates necessary to win the nomination on the first ballot. In the event of a contested convention, it’s expected that Trump would face major obstacles on a second ballot for the nomination as many pledged delegates for him will not actually support Trump when given a free vote. As the Wall Street Journal reported on Thursday, the frontrunner has already lost ground in Louisiana, a state that Trump won on primary night.

• This article was amended on 27 March to clarify that Pat Brady is a former state chair for the Illinois Republican party, and not the current one.