Nancy Caldwell, 60, a secretary at Thonotosassa Elementary School, said the calls and text messages began in July and one of the callers said her number had been listed in an escort ad on classified advertising site Backpage.com, the Tampa Bay (Fla.) Times reported Monday.
"It's very disruptive, but it's very disturbing," Caldwell said.
"I guess this poor Julia gal isn't getting any business," she said of the name given by the ad.
T-Mobile initially told Caldwell it couldn't change her number without a police report, but offered her a change when contacted by the Times. However, Caldwell said her number is listed with the district and changing it would be very inconvenient.
The ad was updated Aug. 10 to change one digit on the phone number.
Liz McDougall, Backpage.com's attorney, said the site has a method of searching for specific phone numbers and blocking ads.
"That's not to say, unfortunately, that we'll get every ad with that number," she said. "That kind of problem happens across the Internet all the time."
McDougall said the site will work with law enforcement if any illegal activity is found to have taken place.