Senami, a 13-year-old girl, was purchased in Benin. "My father didn't want to sell me, but someone put a spell on my uncle and he persuaded my father," she said.
Taken to oil-rich Gabon, Senami slaved as a domestic servant and later as a roadside peanut seller.
With a mixture of rage and sorrow, she recounts her tragic life -- inhumanly long hours, a mat on the floor to serve as a bed and scraps for food.
She worked for a "wicked" Beninese woman in the Gabon capital Libreville who made her "do everything."
"But when she found that 100 CFA francs (15 centimes) were missing she beat me with slippers and then with a stick," she said.
Niakate Tene, 12, was bought by a man in her native Mali for 500,000 CFA francs (760 euros) in 2012 and was forced to marry him.
She was found by the police chained in her husband's home and in tears. Her husband only did a month in prison before being temporarily released.
Senami and Niakate -- their names have been changed -- are among many, possibly hundreds, of foreign boys and girls who toil in Gabon as de-facto slaves.
Yet Gabon is only one of nine West African nations, alongside Benin, Burkina Faso, Cameroon, Ghana, Ivory Coast, Mali, Nigeria and Togo, where the UN says centuries-old exploitation of child labour remains entrenched.
Recruitment for domestic work appears to be the most prevalent form but other types of labour include work in plantations, small trade, begging and soliciting.
The children survive on meagre portions of food and are generally made to sleep on the floor. If they are paid, the rewards are meagre, for the salary goes to the trafficker.
Many youngsters are brought to Gabon through perilous routes, sometimes on rickety boats on winding rivers.
"Six people died during our journey -- we travelled on a dugout canoe for four days," said Senami, who came to Gabon at the start of this year.
Today she lives in a state-run transit centre housing about 80 other rescued foreign children. She only dreams of returning to Benin "to be back with my family and to work for myself."
Child trafficking in West Africa involves a murky, complex web of cross-border greed, said Michel Ikamba, a Unicef official in Gabon.
It entails traffickers in the country where the child is picked up, middle men in a transit nation such as Nigeria, and finally "receivers" in the host country who take the children and put them to work, said Ikamba.
The gang cream off the money from the children's work, said Melanie Mbadinga Matsanga, a member of the Gabonese national committee in charge of fighting child labour.
A child nanny is paid between 100,000 and 150,000 CFA francs (150 to 230 euros) a month but the money goes to traffickers, Ikamba said.
"The child is not paid... and nothing goes back to the home village," he said.
"Trafficked children can work from 10 to 20 hours a day, carry heavy loads, operate dangerous tools and lack adequate food or drink," a Unicef report said.
In Gabon, the phenomenon has reduced since a 2004 law criminalised child trafficking, Unicef said, but could not give figures.
"We have referred many people to the courts and it made an impact," said Sylvianne Moussavou, a lieutenant-colonel in the police who is involved in the fight against child trafficking.
But, she cautioned, many of the children had their ages changed in fake papers produced by the traffickers in order to escape prosecution.
A judge, speaking on condition of anonymity, said some of his peers overlooked certain abuses on the grounds that child labour was an old social tradition and less of a criminal act than child marriage.
And, he said, traffickers or their colleagues often tried to bribe magistrates when they were caught.
"Some judges are turning this fight against child trafficking into a money making machine," he said.
In the meantime, the practice of child exploitation continues.
"I know many people who employ children at home. They know it's illegal but a child costs less," a Cameroonian living in Libreville said.