The Jonas Brothers have steeply discounted their Australian concert tickets after failing to sell out, and fans are not happy.

Some devotees of the band have been left scratching their heads after seeing ticket prices for shows Down Under dropping from hundreds of dollars to much less.

Self-described "lifelong" Jonas Brothers fan Nat McLennan took to social media to express her unhappiness at ticketing company Ticketek, claiming tickets she had bought for around AUD$250 (£128) were being sold for as low as AUD$80 (£41) over the weekend.

"Management put, like, two shows in Sydney and Melbourne and they didn't sell out," Nat explained.

"So now it's the week of the concerts and all these tickets have gone on sale – some were even free 10 minutes before the show last night. My ticket that I bought for like $200-$250, General Admission Standing, is now like $80".

She added that despite her love of the band, she now felt she had wasted her money.

"I feel like I've been ripped off," Nat said. "When the tickets came out, they were expensive, but being a fan it didn't really faze me.

"But now it kind of does faze me because, hello, I spent this money and now it feels like a complete waste."

Commenters were quick to share their own dissatisfactions.

"Paid $250 for GA in Melbourne and now hearing everyone get them for more than 50% off is soo frustrating," wrote one. "Especially in this economy."

"Tell me why I paid $250 for B reserve," wrote another, "and then A reserve ended up being $150 and GA being $79!!!!"