When Melissa, a resident of Halifax, Nova Scotia, went to one of Canada’s first government cannabis stores, she wasn’t impressed. “You can’t look at what they have. You can’t smell the product,” she said. “It’s too expensive.”

And so she, like tens of thousand of other Canadians, went back to their old habits: buying from neighbourhood dealers.

Six months after Canada became the first G7 country to legalise marijuana, the bold experiment is still struggling to get off the ground.

Legal producers were unable to meet the sudden surge in demand, and struggled for weeks to fill orders, leaving marijuana stores with empty shelves.

As a result, the vast majority of cannabis sales in the country – roughly $5bn – are made on the illegal markets, compared to $2bn in legal sales, according to government figures from January 2019.

Ahead of legalization, the prime minister, Justin Trudeau, had argued that the move would nearly eliminate the black market, which he said funnelled money into organized crime.

But with so little cannabis to sell, licensed operators across the country have had to turn away potential customers, sending them instead to the black market.

“When I’m sold out, they’re still gonna find a product somewhere,” said Trevor Tobin, who operates the High North marijuana store in Labrador with his mother, Brenda.

Tobin said running a legal cannabis business has been an “ongoing struggle” in the face of persistent shortages. “It’s hard to keep employees behind the counter when they’re not selling any product – and we lose money every day that we don’t have product on the shelf.”

The Tobins are also competing against illegal “grey market” stores, which alongside marijuana sell edibles and hashish – items that licensed stores cannot yet offer.

A number of government outlets and licensed private stores have also faced complaints that their products do not match the quality of the black market.

“The product I got smelt like barn hay and was just as dry,” wrote one user on the site WeedMaps, reviewing Toronto’s first bricks-and-mortar locations, The Hunny Pot. “The only reason I’ll go back is to get a refund for this purchase.”

Customers and staff at The Hunny Pot in Ontario on 1 April. Photograph: Moe Doiron/Reuters

Melissa agreed: “I found it was really dry. And you feel like you’re getting less as a result. It kind of feels like you’re getting ripped off.” Even her friend, who works at a government store, gets his cannabis from an illegal supplier.

Canadians who purchase their cannabis from illegal sources also save a significant amount of money: the average price for a gram of illegal cannabis is 36% cheaper than its legal counterpart, Statistics Canada has found.

“As long as that price differential exists, there will likely be a black market – because people will go to where they can get a deal,” said Rosalie Wynoch, a policy analyst at the CD Howe Institute, a conservative thinktank. “The government was aware that it wouldn’t fully displace the black market on day one.” She and others suspect the black market will persist for at least another two years, as it did when Colorado legalised cannabis.

Canada is still grappling with how to treat people convicted under the country’s previous laws.

The government has promised to pardon 500,000 Canadians with minor cannabis convictions – but the current rules are still not enough, said Murray Rankin of the New Democratic party and member of the parliamentary justice committee.

Rankin has become a vocal advocate of expunging the records of those with convictions.

“The niceties of the human rights legislation may not be something you’re aware of,” he said. “Even if you were the victim of discrimination, tell me how many people are going to go to the human rights commission with their complaint and deal with it? Frankly not that many.”

Rankin also points to the uncomfortable reality of policing in Canada: visible minorities are over-represented in the number of minor cannabis convictions.

“The disproportionate impact on the hundreds of thousands of Canadians … is something that really should motivate us to not just do the half measure the government’s talked about, but fully expunge so people can get on with their lives,” he said.

Canada will begin the second stage of legalization – the sale of edibles and cannabis-infused drinks – in October.