People who called the Commonwealth Games ticket line were charged while listening to the engaged tone, it has emerged.
Organisers apologised for the problem, which has been blamed on a "human programming error".
Glasgow 2014 said it is working to refund the charges to affected customers "as soon as possible".
The latest glitch comes after the ticket sales website was hit by problems, with customers facing delays of more than 30 hours when extra tickets went on sale on Monday.
The website and phone line have been closed while the issues are investigated and could remain shut for days.
It has been reported that some customers ran up bills of more than £100 while trying to buy tickets through the hotline.
A Glasgow 2014 spokesman said: "Glasgow 2014 can confirm that some callers to the Glasgow 2014 ticket line who received an engaged tone on the ticketing phone lines were charged in error by TalkTalk Business, a supplier of Ticketmaster.
"We apologise unreservedly for this and are working now with Ticketmaster and TalkTalk Business to ensure customers affected by this are refunded these charges as soon as possible."
An extra 100,000 tickets across all 17 sports and the opening and closing ceremonies went on sale on Monday.
A TalkTalk Business spokesperson said: "We are sorry that due to a human programming error, we did not deliver the service that had been agreed with Ticketmaster during the general ticket sale for the Commonwealth Games. This meant that those customers who called the Commonwealth Games ticket line and received the engaged tone were charged for the call in error.
"We apologise unreservedly to all affected customers, Glasgow 2014 and Ticketmaster for this. We will refund each and every customer that has been incorrectly charged."
Customers who think they may be eligible for a refund should email a scan or photograph of their bill, showing the dialled number and call charges to BookingRefund@TalkTalkBusiness.co.uk.
Around 55,000 tickets have so far been sold from the latest ticket release, organisers said.
About 2.3 million applications were made for the initial one million tickets released last year, with athletics, aquatics and cycling proving the most popular events.
BT said it had contacted some customers about their calls to the hotline.
A BT spokeswoman said: "We contact customers if we see unusual or excessive usage on their lines to alert them to the change in their calling pattern.
"In this case, although the caller didn't speak to anyone, the calls were connected to the receiving number and the relevant charges were correctly raised.
"In the last 24 hours, we've warned a very small number of customers about their calls to Ticketmaster. BT is not part of the Glasgow 2014 ticketing operation."
Speaking on a visit to Glasgow, Prime Minister David Cameron said: "There are always some problems when you've got such a complicated set of things to get right, right across the piece. There are always some things that need some last minute attention.
"I'm sure that this will be sorted out, I am sure that the Scottish Government will get on top of it straight away, and what I see is the preparations going well for a successful games."
Why are you making commenting on The Herald only available to subscribers?
It should have been a safe space for informed debate, somewhere for readers to discuss issues around the biggest stories of the day, but all too often the below the line comments on most websites have become bogged down by off-topic discussions and abuse.
heraldscotland.com is tackling this problem by allowing only subscribers to comment.
We are doing this to improve the experience for our loyal readers and we believe it will reduce the ability of trolls and troublemakers, who occasionally find their way onto our site, to abuse our journalists and readers. We also hope it will help the comments section fulfil its promise as a part of Scotland's conversation with itself.
We are lucky at The Herald. We are read by an informed, educated readership who can add their knowledge and insights to our stories.
That is invaluable.
We are making the subscriber-only change to support our valued readers, who tell us they don't want the site cluttered up with irrelevant comments, untruths and abuse.
In the past, the journalist’s job was to collect and distribute information to the audience. Technology means that readers can shape a discussion. We look forward to hearing from you on heraldscotland.com
Comments & Moderation
Readers’ comments: You are personally liable for the content of any comments you upload to this website, so please act responsibly. We do not pre-moderate or monitor readers’ comments appearing on our websites, but we do post-moderate in response to complaints we receive or otherwise when a potential problem comes to our attention. You can make a complaint by using the ‘report this post’ link . We may then apply our discretion under the user terms to amend or delete comments.
Post moderation is undertaken full-time 9am-6pm on weekdays, and on a part-time basis outwith those hours.
Read the rules hereComments are closed on this article