Frustrated callers tweeted HM Revenue and Customs (HMRC) more than 11,500 times over the past year to complain about long waits to be answered, according to a charity.
Citizens Advice says those who complained via Twitter claimed to have spent an average of 47 minutes on hold waiting to speak to someone at HMRC, despite official figures suggesting an average wait time of 10 minutes.
The charity looked at complaints made to the @HMRCgovuk Twitter account between September last year and August 2015 after those seeking help from the charity reported not being able to get through to HMRC to resolve their issues.
In one case it saw, one caller tweeted that they had tried to get through to HMRC on four occasions, waiting an hour each time.
Of course, this is just one avenue of complaints so doesn't come close to detailing the full horror.
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Tax credits hotline hell
Citizens Advice said it helped with 295,000 queries in the past 12 months which could have required people to contact HMRC.
Three out of four of the cases specifically related to tax credits, while others included income tax, National Insurance contributions and child benefit.
Each year MoneySavingExpert.com warns people not to wait until the 31 July tax renewal deadline approaches to contact HMRC with queries as calls peak during that time and phone lines get jammed.
But this April, we covered how the first batch of tax credit renewal packs were being sent out by HMRC where furious recipients said they were already facing long waits on the helpline incredibly worrying as the deadline, and real peak for queries, were still a few months away.
At the time, HMRC told us the best times to call were between 8.30am to 10.30am and between 2pm and 4pm Tuesday to Thursday. And today it adds that callers wishing to get through to any department at HMRC should call early morning or late afternoon when it's less busy.
In June we reported how HMRC had set aside £45m to improve customers service after figures showed that 7.2 million phone calls made to it last year went through to a busy tone instead of the caller being put through to speak to someone.
'HMRC needs urgently address the problems with phone lines'
Citizens Advice chief executive Gillian Guy says: "People are paying the price for not getting through to HMRC. From fines for not completing a tax return in time to under or overpayments for tax credits, people can be left out of pocket because they cannot speak to HMRC on the phone.
"We have consistently raised this issue with the Government. But evidence from across the Citizens Advice service, and our new research, shows HMRC is still failing to provide a timely service.
"There is already a clear demand to be able to speak to HMRC. With the roll-out of Universal Credit and big changes to tax credits just around the corner this is only going to grow. HMRC needs to urgently address the problems many people are experiencing with phone lines."
'We are sorry some customers have struggled to get hold of us'
An HMRC spokesperson says: "We are sorry that some customers have struggled to get hold of us, but this unscientific and out-of-date survey of tweets does not represent the real picture now.
"In reality, answer rates on our phones are improving and wait times are falling. HMRC is quick to deal with peaks in demand by moving staff internally and taking on additional people. These steps helped us to handle more than 90% of calls on tax credit deadline day.
"And while customers will still be able to call us if they wish, we have developed quick and easy to use digital products to provide more choice for our customers such as online renewal for tax credits and web chat for people who need support. This is how people deal with other services now and this is how they want to deal with HMRC."
Additional reporting by the Press Association.