AJet Blocked My Check In Due to One Letter in My Name

We bought a four-person ticket from AJet through Booking.com. There’s no issue with three of the passengers, but the fourth person—the children's mother—cannot check in. Her name is “Nurgül,” but in the AJet system, it appears as “Nurguel.” Because of this, we’re getting an error saying the name, ID number, and date of birth do not match. I called AJet 2–3 weeks ago, and they said this kind of spelling difference wouldn’t be a problem. But today, on the check-in day, we’re unable to proceed. I’ve contacted Booking.com, AJet, and the intermediary company Petur, but none of them could resolve the issue. We've been dealing with this for hours over a single letter, and they keep saying, “We’ll get back to you,” but no one does. I’m always the one calling back. Please resolve this immediately—our flight is tomorrow at 08:10 AM.