Ozzy Osbourne fans have complained that they have not officially been told whether his UK tour has been postponed and whether they will get refunds, three days before it is due to begin.
The arena tour, due to start on Friday in Newcastle, is still in the venues' listings, with tickets still on sale.
Sharon Osbourne and support band Judas Priest have both said it is off, but ticketholders haven't had confirmation.
"It's not fair to keep people in the dark," fan Gregor McCormick said.
"It's ridiculous. They need to keep people up to date."
The former Black Sabbath frontman's No More Tours 2 tour is the only pop or rock tour still in the schedules on the arena websites this side of 2021. All others have been called off because of Covid-19.
Mr McCormick, 57, from South Ayrshire, has tickets to see the Prince of Darkness in Glasgow on Sunday, the tour's second night. He, his brother and cousin spent £230 on their tickets in total.
"We haven't had any definitive 'Yes' or 'No'," he said. "Obviously in our own minds, with Covid-19, we know this is not going ahead. But people have spent hundreds of pounds. Not giving us information is absolutely diabolical.
"I appreciate there are probably huge logistical problems that these promotional companies have to deal with. But it is extremely annoying to be left in the lurch, to not know what's happening.
"And there are huge knock-on effects, particularly when we are travelling from such a distance. It's not just a case of not knowing when the concert is. We don't know when we should attempt to book hotels and all these things. It's a lot of stress. You spend a lot of money to follow these bands and these artists."
'Annoying and frustrating'
Another fan, Ben Black, 40, from Northumberland, said: "The only thing I've seen is third-party sources on the internet saying it's not going ahead. People need advance warning.
"The annoying thing is we know it's not happening because they've got the whole government lockdown and restrictions. They've cancelled people attending a football stadium, so to have thousands of people inside a confined arena - you know it's not going to happen.
"It's just annoying and frustrating that no-one's forthcoming and saying, 'It isn't happening, we are looking at getting new dates set up'."
The tour was originally scheduled to start in January 2019, but was postponed because of illness. It was rescheduled to run from January 2020, but that was also pushed back. Osbourne has struggled with his health in recent years, and this January revealed he had been diagnosed with Parkinson's disease.
Speaking to Planet Rock earlier this month, Sharon Osbourne, Ozzy's wife and manager, said the tour had been rearranged for 2022.
"Everybody's booking their tours again for like 2022, and to find availabilities right now, it's crazy," she said. "Agents and facilities are going nuts, trying to get everybody back."
On Friday, Judas Priest tweeted to say the tour was being put back "due to the ongoing issues with Covid-19".
Unfortunately due to the ongoing issues with COVID-19 the Ozzy Osbourne/Judas Priest UK/European 2020 tour has had to be rescheduled to 2022...as soon as we have all the dates finalized we will announce them...in the meantime wear your masks, wash your hands and stay safe! pic.twitter.com/BCJ5C6xAmE— Judas Priest (@judaspriest) October 16, 2020
Jenna Smith, 37, who has tickets for her home city of Glasgow, said the lack of a similar message on Osbourne's official channels was "really unprofessional".
She said: "I feel that the fans have been treated badly by Ozzy's management. Obviously we are in the midst of a global pandemic so luxuries such as concerts need to wait, I was happy to wait for another date once this is over and Ozzy is healthy.
"But to be ignored after buying expensive tickets and already waiting two years since they were purchased is making me feel like we don't matter and they're just holding on to our money."
A spokesman for Osbourne said the tour was postponed but referred the BBC to Live Nation, the tour's promoter. Live Nation has not responded to a request for comment.
A spokeswoman for Nottingham's Motorpoint Arena, where Osbourne is due to play his final UK show on 8 November, said: "We have to wait for a promoter to tell us when a show is cancelled or rescheduled. Until then we can't do anything with our listing."
There was no comment from the other venues or Ticketmaster. After the UK and Ireland, Osbourne's website lists his tour as continuing through Europe, finishing in Helsinki, Finland, on 7 December.