Potential customers at the troubled Bath Spa have been kept waiting so long on a telephone booking line they have given up in disgust.
The spa was due to open in 2002, but a series of rows delayed it
The website of the £35m spa, which opened in early August, refers would-be customers to a telephone booking line.
But many have given up after being left holding on for more than 10 minutes. One potential user told the BBC: "It was an exasperating 10 minutes."
Peter Rollins, of the spa, said the problem was being addressed.
He said: "We are trying to improve the service as quickly as humanly possible.
"We understand that people are waiting an unacceptable period of time. But it's not just the volume of calls, but actually the length of each call that is creating a backlog.
"Some calls are taking nine minutes to deal with.
"We want to engage the services of a call centre so they can deal with general inquiries. We know we've got to improve the service."
The spa was originally planned as a £19m Millennium Project, but bitter rows and court battles with contractors saw costs rocket to more than £35m.
An NHS spa treatment centre on the site was closed on health grounds in 1978 and attempts to restore the spas failed because of costs and concerns over the purity of the water's source.
But in 2000, the Millennium Commission gave a grant of £7.78m to refurbish five listed buildings within the complex, including the 18th Century Hot Bath and Cross Bath.