Organisers of Sydney's Lost Picnic festival have apologised to punters demanding refunds following reports that there was an average wait time of 60-90 minutes in the food and bar lines on Sunday. 

In a statement released on Monday, organisers of the boutique event responded to the overwhelmingly negative feedback posted on its Facebook page.

"Lost Picnic 2017 was nine months in the making and we continually strive to put on high end, quality events," the post reads.

"We sincerely apologise for the long wait times and agree there were numerous operational issues on the day. We will be addressing all of these well in advance of next year."

The queues were reportedly so long that some spent most of the event lining up to collect pre-purchased hampers and drinks, missing out on headline acts Sarah Blasko, Fat Freddy's Drop and more.

See the full statement below.