Digna Batista was promised she would be heading to paradise when she paid people smugglers to take her from the Dominican Republic to Chile. Instead, she found herself walking across a desert minefield to encounter a less than sympathetic welcome in a society that is struggling to accommodate a growing number of migrants from the Caribbean.

Discrimination, labour abuse and outdated immigration policies have made adjustment difficult for many among the more than 50,000 Haitians and 15,000 Dominicans who are part of an economic migration story that is quickly moving up the political agenda before a presidential election later this year.

Batista borrowed more than $2,500 to pay coyotes (the people smugglers) for the journey across the Andes and the Atacama desert in the hope of finding a better life.

Leaving her three-year-old son behind, she first flew to Ecuador, where she continued by bus – at one point crushed with 17 others in the luggage hold – on the 3,000km overland route through Peru to the Chilean border. Once there, she and the others were told to head towards a distant light.

“We walked all night. Finally, in the morning, we got to a road, stopped a passing taxi and asked the driver to take us to the nearest hostel. He told us we’d just walked through a minefield,” she recalled.

The dangers are all too real. More than 90,000 mines were laid by the Chilean military in the 1970s – a time of dictatorship and paranoia about Peru. Although the army subsequently promised to decommission them all by 2012, progress has been slow and about 40,000 are still in place. Warning signs are either inadequate, misplaced or ignored by desperate migrants. Last year, a 24-year-old Dominican, Daniel Sosa, lost his left foot when he stepped on a mine trying to enter the country illicitly to find work after being denied a visa.

A string of such incidents – some of them fatal – have caused growing diplomatic concern that Chile’s border policies are driving people to risk illegal crossings. The Dominican Republic consul in Arica, Nina Consuegra, said Chile’s PDI border police are now stopping and denying entry to anyone who is either black or Venezuelan if they fail to show pre-paid hotel vouchers and return tickets.

But even those who arrive legally face prejudice.

Until the 1990s, Chile had only a small black population, so the recent arrival of a black migrants has caused a stir.

History suggests this ought not to be the case. A 2014 genetic study found that one in two Chileans had ancestors among the thousands of African slaves brought to the country between the 16th and 19th centuries. But Chile’s elite have long preferred to emphasise their country’s European roots and the newcomers are now the subject of a growing debate.

“[The migrants] are often very badly discriminated against,” says sociologist María Emilia Tijoux. “Some are really suffering. And it’s not just a legal problem, it’s because there’s a part of Chilean society that’s so damned racist.”

Batista says she has experienced kindness and hostility.

She now works as a maid in uptown Santiago while trying to legalise her residency so that one day she can bring her son Brayan to live with her.

Many Haitians find low-paid niches in the labour market where Chileans are reluctant to work, particularly construction, domestic service and agriculture.

Lacking full legal rights, some are exploited, said Haitian community leader Widner Darcelin, who said migrants sometimes work for months without being paid.

Earlier this month, a homeless Haitian migrant named Joseph Polycart died of hypothermia after he was twice turned away from a local hospital on a freezing night.

But there are also positive stories. N’kulama Saint Louis arrived in Santiago with his wife Patricia and two-year-old son N’kulahi in 2010, following Haiti’s devastating earthquake. Today N’kulama works as a street-sweeper, and studies sociology at the Catholic University by night. “We got a lot of support from our Chilean friends,” he said, “but the government doesn’t have a comprehensive immigration policy and that’s a huge problem.”

The current system is widely criticised as outdated. One notorious immigration law – a holdover of the Pinochet dictatorship – intrinsically views all migrants as potential subversives, said Jean Claude Pierre-Paul, a Haitian social worker.

And the situation could get worse. The centre-right candidate in the election, former president and billionaire businessman Sebastian Piñera, is following the example of Trump in the United States and Argentina’s Mauricio Macri by proposing tighter border controls and the expulsion of all irregular migrants – an estimated 150,000 people.

Given Chile’s enormous 5,000km frontier, there is no suggestion of a border wall, but tighter regulations alone could drive more migrants to attempt risky illegal crossings of mountains, deserts and minefields.

“Visas don’t control migration – migrants will just turn to people smugglers to enter the country,” said Rodrigo Sandoval, head of the ministry of the interior’s immigration department.

Sandoval said Chile needs a new immigration law that helps to attract more outsiders to offset the country’s aging population and labour shortages. His proposals have prompted a rightwing backlash on social media, where xenophobes describe him as a traitor who is allowing Chile to be “invaded.”

Cooler heads urge self-reflection. In the Independencia neighbourhood, social worker Patricia Loredo, who helps run the Sin Fronteras migrants rights collective, believes Chileans need to be much better informed and educated about their heritage.

“Most Chileans don’t have a clear idea of their cultural identity,” she said, “but this is clearly a mixed-race society.”