Li Hongbin, from a village in poor northwestern Gansu province, dropped out of school last year and began calling the expensive hotlines in August.
He committed suicide by drinking pesticide after a telephone company clerk called at the family home asking for payment.
The longest conversation listed in a 16-page phone bill went on for over four hours, Xinhua said.
Calls cost three yuan a minute, Xinhua cited the head of one service as saying. The average monthly cash income of Chinese farmers is just 300 yuan.
Phone sex services have been proliferating in recent years, with adverts in local telephone directories and newspapers, but Beijing is also attempting to crack down on pornography with a campaign that includes monitoring phone sex lines.
($1=7.828 Yuan)
