A New Jersey woman who bought Broadway tickets online to celebrate her 9-year-old daughter's birthday says they were turned away at the theater because the tickets were invalid. 

For weeks, she was unable to get a refund from the site where she purchased the tickets, StubHub, a secondary ticket marketplace where fans buy and sell seats.

So, she turned to the CBS News New York investigators to get results and warn others about what to know before clicking buy.

Tickets would not scan at the venue

On the day of the show, Courtney DeRocini went to the theater and showed them the QR code for the tickets in the StubHub app.

"They went to scan my phone. [The usher] said it's not coming up," she said. "He said, 'Don't worry, a lot of times this happens ... Usually around 7:00, you get tickets and you're able to get in.' I said, OK. Now, in my head, I'm wondering, what is going on here?" 

StubHub sent DeRocini multiple replacements, but none of those worked either, she said. 

"My 9-year-old is crying. She loves 'Mamma Mia!' She wants to see the show," she said. 

The mother and daughter wound up missing the show while DeRocini was on the phone with customer service.  

StubHub did not immediately issue refund, despite "FanProtect" promise

After three weeks without a refund, DeRocini reached out to CBS News New York. 

"I decided to contact you because I watch CBS and I've seen you help other people with different things," DeRocini said. 

StubHub's "FanProtect" guarantee promises "valid tickets or your money back." We contacted the company and DeRocini got her refund. 

"We are very sorry for Ms. DeRocini's experience and regret that she and her daughter missed the show. This is not the standard StubHub strives to deliver," the company said in a statement to CBS News New York. "Under our FanProtect Guarantee we have issued her a full refund, including her prepaid parking. We have also provided a voucher for future use. We are also strengthening seller compliance and ticket verification measures to help prevent this type of situation from happening again."

The company said the refund was delayed due to a technical misstep. 

Things to keep in mind when buying tickets online

To avoid finding yourself in a similar predicament, keep these things in mind when shopping online for tickets:

• Consider buying tickets from the box office when you can.
• Always use a credit card, since it gives you more protection if you need to dispute a charge.
• Keep your records, including emails and screenshots, in case you need proof the tickets did not work. 

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