LAS VEGAS – A Las Vegas middle school teacher is fuming after her teachers union denied her request to leave the union, and now she’s on a mission to ensure union officials regret the decision.

Robison Middle School teacher Cindy Robertson doesn’t think the Clark County Education Association’s representation is worth the union’s exorbitant dues, so she made sure to comply with the union’s strict two-week window to drop her affiliation, KTNV reports.

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For years Robertson has attempted to leave the CCEA, but is typically on vacation during the only two week window the union accepts withdrawals – between July 1 and July 15.

“This year I made sure I had the letter ready ahead of time, and I mailed it to make sure I didn’t miss the window,” she said.

Robertson sent out her withdrawal letter in mid-June, well before the deadline, because she was leaving for vacation on July 2, she said.

When Robertson returned on July 16, the day after the window closed, there was a letter waiting in her mailbox from the CCEA, according to the news site.

“Just as the window was opening they mailed me back a letter telling me I would have to redo the letter or come in before the 15th,” Robertson said. “They absolutely insisted that I could have mailed my letter from anywhere in the world and that I can try again next year.”

Robertson told KTNV she thinks the union charges a lot more for dues than it’s worth.

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“Why are you charging union sized dues? It is $780 plus per year out of my paycheck if you are not going to come and speak with me when I need some assistance,” Robertson said. “They’ve always told me they just do contracts. That they are just a collective bargaining unit.”

The teacher said she doesn’t think the union’s withdrawal rules make any sense.

“As far as I was concerned, what does it matter the postmark on the envelope. You open the envelope, you throw the envelope away, the letter says July 1,” she told the news site.

Robertson said she’ll comply with the rules this year and pay her CCEA dues, but her experience this summer convinced her to launch a personal crusade to help other disgruntled union teachers to drop their CCEA affiliation, as well.

“Now I’m going to encourage other people that are unhappy with the union,” she told KTNV. “I am going to teach them how to write the form letter so they can do it too.”

The news site attempted repeatedly to contact union officials about the very narrow withdrawal window, and Robertson’s case in particular, but they ignored the news stations calls and emails. A KTNV reporter also stopped in to the union office on multiple occasions but was told officials were unavailable.

The CCEA’s decision to reject Robertson’s request to leave is the latest in a long line of questionable decisions by union officials, a major reason why the Nevada Policy Research Institute and other groups have worked to help teachers drop out of the union, EAGnews reports.

The NPRI campaign convinced 470 Las Vegas teachers to quit the CCEA in 2013.