Meanwhile, customer complaints mounted over high prices and poor service, and prominent members of the US Congress backed public pleas for the Department of Justice to investigate Ticketmaster on anti-competition grounds.
The American singer's Eras tour, her first in five years, had already set the entertainment industry abuzz. In the "pre-sale" round on Tuesday, more than two million tickets were sold, the most ever for an artist in a single day, Ticketmaster said.
Even so, the experience left many fans frustrated with long wait times and site outages, and many unable to obtain tickets.
It was not immediately clear when the remaining tickets might go back on sale.
Ticketmaster representatives did not immediately respond to interview requests to answer the criticism, but the company, whose parent is Live Nation Entertainment Inc, acknowledged the difficulties encountered by fans.
Ticketmaster said a record 3.5 million people had registered as verified fans, the largest number ever.Â
It said it had planned to invite 1.5 million of those to take part in the sale for all 52 show dates, including the 47 sold by Ticketmaster, with the other two million placed on a waiting list.
But the plan, it said, was undermined by attacks by bots and demand from those who had not previously registered.
Swift's 20-city, 52-date stadium tour will begin in March in Arizona and end in August in Los Angeles.
The troubles prompted members of the US Congress to raise questions about the 2010 merger between Live Nation and Ticketmaster, which created a company that dominates the market.
"I've long urged (the Department of Justice) to investigate the state of competition in the ticketing industry," US Senator Richard Blumenthal said on Twitter.
US Representative Alexandria Ocasio-Cortez linked to an online petition that urges the Justice Department to break up Ticketmaster.
In a letter to Ticketmaster, senator Amy Klobuchar, chair of the Senate antitrust panel, voiced "serious concern about the state of competition in the ticketing industry and its harmful impact on consumers".
