TORONTO -- Ontario's ombudsman says complaints about the provincial agency responsible for enforcing court-ordered child and spousal support payments are growing every year.

Andre Marin says he received 1,167 complaints about the Family Responsibility Office in 2014-15, a slight increase over the previous year but up considerably from 794 complaints two years ago.

Marin says the agency had to reimburse 350 people about $845,000 in retroactive payments when they were wrongly denied all benefits after they stopped being eligible for welfare or disability support.

In his annual report, Marin says there are also serious problems in cases where the person paying the support or the recipients live outside Ontario, something he has raised in previous years.

The ombudsman has frequently warned about poor customer service and mistakes that denied or withheld support payments from eligible single parents and their children.

Marin, who hopes to be reappointed for a third, five-year term as ombudsman, says Hydro One received the most complaints for the second year in a row after it implemented a new, and flawed, billing system.