Turkish Airlines Didn't Allow Me to Board Due to Misleading Staff

I am a mother of twin babies. I had to travel as the sole guardian and, since I had to go from the district to the city center, I purchased my ticket after thoroughly questioning the customer representative. Upon arriving at the airport, I was confronted with an issue stating that I could not travel with two babies as a sole guardian. However, I was told that I could travel by holding one baby in my lap and placing the other in a car seat next to me, and purchasing a child ticket for the second baby. I paid the extra fee as instructed by the representative, but I was not allowed to board the flight. Another passenger was added for my other baby, and I had to pay an additional ticket fee for my baby again. I was given incorrect information and, despite having voice recordings, I paid extra money. I sent feedback to Turkish Airlines three times. Each time, they produced a false excuse stating that I was not allowed to board because I did not bring a stroller. This situation is very shameful and unacceptable. If there are cameras, they should be reviewed hour by hour, and my refund should be processed. I am deeply disappointed by this experience.