AUSTIN (KXAN) — Nancy Spaniola doesn’t use toll roads often — only the occasional drive to visit her boyfriend’s parents.

“They live in Georgetown off 130 and I live in Pflugerville, so I drive up there to take them food or groceries,” she told us.

Yet she knew something wasn’t right when 55 different $20 charges were withdrawn from her bank account, her TxTag one.

“That amounted to $1,100,” said Spaniola.

Spaniola says she did the legwork, and waited on hold with TxTag representatives. The toll authority provided Spaniola her driving activity from late-November to mid-February. The documents show every toll she drove through during that period amounted to $99.03.

“[The TxTag representative] said it was a system glitch, and they had no idea why the system was doing multiple charges to people,” Spaniola recounted.

For months, our investigative team has been reporting on the rollout of a TxTag system upgrade, which has been beset by technical problems. The toll authority, which is funded by the Texas Department of Transportation, said customers would start to see multiple charges posted to their account that were incurred from late October 2020 to January 2021.

But several drivers tell KXAN the newly-posted charges are far more money than their driving habits would indicate during that time period. Others are still calling TxTag, trying to find out if they’ve been overcharged and by how much.

“I would say if anyone has autopay set up, turn it off,” said Spaniola.

As a result of the overcharges linked to the system upgrade, TxDOT says it has refunded $5.1 million to customers. A department spokesperson said the issues are technical in nature, but did not provide specifics on the problem.

“Accuracy of customer activities and charges remains a top priority for TxDOT,” the spokesperson said Monday. “We are diligently monitoring for isolated incidents that impact customers and will resolve any issues identified as quickly as possible as evidenced by the amount of refunds processed.”

Bill Stephan is another driver who sought more specifics on the newly posted charges to his TxTag account, only to learn he had also been overcharged.

“I really did not expect there to be huge overbill issue,” said Stephan. “That was kind of a surprise.”

Bill Stephan said he sent he went all the way to top for answers, sending a direct message on Twitter to TxDOT Executive Director James Bass. The conversation was confirmed by the department.

“Apologize for this happening,” Bass told him, according to a screenshot of the conversation. “We continue working with the contractor to get resolutions as quickly as possible.”

Stephan said two days later, the toll authority called him and acknowledged he was owed a refund of $160.

“All of the additional work that is having to happen now at TxDOT for rectifying the problem is a huge cost to the taxpayers in getting this fixed,” he said.

Meanwhile, Spaniola says she is still waiting for her refund.

“They said it might be 30 days. Thirty days could be an eviction for some people at this time in their lives,” she said. “I just happened to have some extra money that I was able to cover this $1,100.”

While TxTag has acknowledged the problems, a spokesperson did not answer direct questions about why system upgrades have taken longer than expected.

“We continue to evaluate ways to improve the system and work with our vendor to solidify the timeline,” said the spokesperson. “We are working through this and are committed to quality and customer service.”

At the same time, TxTag is touting new improvements to its “mobile-friendly website and enhanced customer service features.” The toll authority says it has not been charging late fees since the upgrades began late last year.