CHICAGO (CBS) — Despite flaws that have prompted the CTA to halt the switchover deadlines for Ventra, Mayor Rahm Emanuel defended the new fare system on Wednesday, saying “debacle” is too strong a word for the problems, as one alderman described it.

“First of all, 55 percent of the people are using it,” Emanuel said.

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WBBM Newsradio’s John Cody reports the mayor acknowledged the new Ventra system is not working the way it should, and said “they won’t get paid until it does do that.”

“That means holding them accountable, and making sure that … their feet are being held to the fire,” he added.

Emanuel said CTA President Forrest Claypool has done a lot to modernize CTA train stations, rail lines, and security systems; and backed Claypool for his effort to get Ventra contractor Cubic Transportation Systems to bring the $454 million fare system up to speed.

Claypool said Tuesday that the previous deadlines for CTA riders to switch to Ventra cards have been suspended until the problems are fixed. He said Cubic won’t be paid a dime until 99 percent of fare card machines and readers are working, 99 percent of customer service calls are answered in five minutes or less, and 99 percent of Ventra readers register fares within 2.5 seconds.

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Originally, the CTA was going to stop accepting fares from the Chicago Card and Chicago Card Plus on Nov. 15, and was going to stop accepting magnetic-striped fare cards on Dec. 15. Both deadlines have been suspended indefinitely.

The rollout of Ventra has been plagued by complaints that riders cannot activate their cards, have been charged multiple times for one ride, and have been unable to reach a customer service agent when calling Ventra’s hotline.

Ald. Bob Fioretti (2nd) called the switchover a “debacle” and said the City Council Transportation Committee should question Claypool and CTA Board Chairman Terry Peterson about the Ventra problems.

Fioretti said he’s been unable to activate his Ventra card, despite trying three times to get through to a Ventra call center operator — twice after 8 p.m. on a weeknight and once on a Sunday. He said he was disconnected, or hung up in frustration after waiting up to 45 minutes.

Claypool said he has ordered another call center be opened to handle complaints.

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Cubic executives have apologized for the errors, and vowed to fix them, but neither Cubic nor the CTA has given an estimate as to when Ventra will be running properly for all riders.