Getting the National Broadband Network connected to his Blue Mountains home has been a nightmare for Tim Harvey — and the ordeal is not yet over.

Key points: Tim Harvey has been told his ADSL connection will be stopped from next month but he has no NBN at home

Tim Harvey has been told his ADSL connection will be stopped from next month but he has no NBN at home NBN Co's rollout map shows some of his neighbour's are also without access

NBN Co's rollout map shows some of his neighbour's are also without access The company apologised for Mr Harvey's experience but said it was the exception, not the rule

Mr Harvey, an engineer who works from home, can't connect to the NBN despite it being available in his area for years.

To make matters worse, his current ADSL provider, iiNet, has told him it will stop supplying the service from next month.

"I don't want to be in the position where my internet's cut and I can't work," Mr Harvey told the ABC.

Across Australia, the rollout of the NBN is on track to be completed by mid-next year.

While complaints about the service are falling — with 6.7 complaints per 1,000 new sites connected in April 2019, compared to 9.2 complaints per 1,000 reported in 2017 — customers like Mr Harvey are still having problems simply connecting.

Complaints about the NBN have fallen over the past two years. ( ABC News: James Oaten )

But according to experts, he is not the only one having problems.

"There are quite a lot, a couple of hundred thousand problems, that NBN Co has not been able to solve immediately," independent telecommunications analyst Paul Budde said.

"Rather than include them in the rollout, they say we'll leave that as is, and we'll actually start looking at them later," he said.

Mr Harvey has bought a wireless dongle to make sure he can continue to work, but he worries about others.

"It's not just about me … there must be a lot of other people who must be experiencing this, even on my own street," he said.

Terrain 'difficult' for installation

When the ABC questioned NBN Co about Mr Harvey's experience, it apologised and said his case was "the exception, not the rule".

"The rollout of the NBN is extremely complicated and in this case — which is the exception, not the rule — we haven't been able to provide a connection to Mr Harvey," spokesman Ryan Williams said.

Mr Williams said NBN Co was working closely with Mr Harvey to ensure a temporary solution was in place.

He said terrain in the Blue Mountains could add to installation issues.

"If we take a place for example like the Blue Mountains, there's rock, difficult terrain, premises spread far apart," Mr Williams said.

"We work really hard to make sure we get a connection to every single home as quickly as possible, but due to some of those circumstances, it does take some premises a little bit longer to get connected."

NBN Co's own online rollout map shows that some of his neighbours are also without access.

Since being contacted, NBN Co has also moved forward scheduled construction works in the area, to try and have Mr Harvey and others connected by the end of next month.

NBN sets goal of completion in 2020

Mr Budde said Mr Harvey's difficulties connecting to the NBN were unusual.

"You've got situations where individual homes have this problem, but I've not come across a lot of situations where there is no solution whatsoever," he said.

Mike Schraft says he's happy with his connection. ( ABC News: Jonathan Hair )

"Mostly, NBN Co then actually makes sure that the existing connection remains in place, they can then solve that problem later," he said.

The NBN began rolling out in Sydney in 2015 and is expected to complete the job nationally by June next year.

Sixty-five per cent of the city can access to the network.

Not all customers have had difficulty with the NBN.

Mike and Libby Schraft run a small business from their home in Cronulla and, once they managed to get online, have been happy with the service.

"We had a few hiccups, in terms of getting the NBN connected, however, once we got it connected, within 10 minutes we were up and running," Mike Schraft told the ABC.

"Once we got the connection, it's been terrific," he said.