TORONTO -- Grievances from frustrated pot customers have given the Ontario Cannabis Store the dubious distinction of being the government organization that was the subject of the most complaints to the province's ombudsman.

More than 2,400 Ontario residents complained about the government's online marijuana store in the wake of delays and delivery problems, the ombudsman said in his annual report released Tuesday.

The OCS was the single most complained-about government organization of the past fiscal year, with 2,411 concerns filed, Paul Dube said. There were more complaints about correctional facilities -- 5,711, up 14 per cent from last year -- but they are spread out over various institutions.

The ombudsman's office had to establish a dedicated team to handle the volume of cannabis complaints, which included a man receiving an empty box instead of his order and being told he would have to return it.

"OCS officials told him he could place a new order without charge, but he would first have to print out a return shipping label, attach it to the empty box, and send it back to them," the report said. "Faced with the absurdity of having to return an empty box for a refund, he complained to our office."

When recreational marijuana became legal on Oct. 17, 2018, the online store was the only place to purchase legal recreational pot in the province, as brick-and-mortar stores didn't start opening until April.

The OCS had warned on its website that delivery times for orders may be longer than expected due to "unbelievably high demand" and labour action at Canada Post.

Most of the complaints to the ombudsman about delivery delays, lack of communication and customer service issues came within the first three weeks, Dube said.

"I don't know if the lead time was insufficient, but they just did not anticipate the demand," he said. "I had the image of a couple of kids on a wharf with a lemonade stand and a cruise ship showing up."

A spokeswoman for OCS said now nearly 99 per cent of all orders are delivered within one to three business days.

New Democrat Marit Stiles said any government embarking on cannabis legalization should have foreseen what would happen.

"If you didn't know there was going to be a massive demand for cannabis once this was rolled out, you really missed something big that's been happening in Ontario for a long time," she said.

The Ontario Autism Program was one of the other top areas of complaint -- 575 complaints were received, with all but six of them coming after the government announced a new program in February.

The program gives each family up to $20,000 a year until their child turns six, and $5,000 a year until age 18, and Dube said many of the complaints were about the funding cap.

The government has since said it will look at how to provide needs-based supports -- and shuffled out the minister -- after families protested that the amounts weren't nearly enough, particularly for kids with severe needs whose therapy can cost up to $80,000 a year.

In corrections, the ombudsman's office fielded complaints about access to health care, segregation placements, use of force by correctional officers, inmate-on-inmate assaults, a lack of Indigenous services, overcrowding, lockdowns, issues affecting transgender inmates, and voting.

Other government organizations that received high volumes of complaints include the Family Responsibility Office, the Ontario Disability Support Program and Tribunals Ontario.

The cancellation of an electric vehicle incentive program also led to more than 300 complaints.

The ombudsman now has responsibility for oversight of French language services and children and youth, after the Progressive Conservative government eliminated those offices. Those units within the ombudsman's office are largely staffed by employees from the formerly separate bodies, Dube said, and have dealt with hundreds of complaints since May 1.