By Brian New

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DALLAS (CBS11) – When you call 911, you expect to hear the voice of an operator within seconds, but on Saturday in Dallas some callers waited more than 30 minutes.

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Operators were flooded with hundreds of 911 hang up calls that were not even real.

The City of Dallas said a T-Mobile software glitch known as “looping” is causing the problem.

Here’s how it happens.

A person on a T-Mobile cell phone will make a single call to Dallas 911, but the 911 call center is not receiving just a single call from that number.

That same phone number gets reported as a hang-up call and it can happen again and again. It’s looped back into the system. Per policy, 911 operators have to respond to each and every one of these reported hang up calls. This wastes the time of operators while leaving other callers on hold.

This T-Mobile software glitch was first noticed by Dallas 911 operators back in October. The city said at the time it wasn’t any causing significant hold times.

That changed in January.

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Councilman Philip Kingston said he first learned about the 911 T-Mobile problem after receiving a call in January from a constituent who told him he had been placed on hold for 25 minutes after calling 911.

Kingston said the moment that happened the city should have sounded the alarms.

“For someone to have this problem at the 911 center and know that we are putting people on hold and not immediately raise an alarm, that’s a mistake,” he said.

Wednesday afternoon, the city manager admitted the city thought they had fixed the problem back in January but operators reported more issues in February,

The Dallas Police Department first alerted the public about the T-Mobile issue on its blog on February 7. The city put out memo addressing the issue a week later.

However, the Mayor’s Office said behind the scenes the City had been talking with T-Mobile every day since November.

Mayor Mike Rawlings said he is very frustrated at how long this has taken to fix.

“I don’t believe T-Mobile has had the sense of urgency that we’ve needed in the city. I’m hopeful they’ve finally got that sense of urgency,” said Mayor Rawlings.

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A spokesperson for the FCC said the federal agency is aware of the issue and that “its review is ongoing.”