Turkish Airlines Cabin Baggage Size Issue

I was entitled to carry a cabin-sized baggage for my international trip. After reviewing the dimensions listed on the THY website, I checked products with dimensions of 23x40x55 cm. I called customer service to confirm that the suitcase I wanted to buy had dimensions of 25x35x57 cm. The representative informed me that as long as the sum of these three dimensions did not exceed 118 cm, it would be acceptable. Based on this information, I purchased the suitcase. On the day of the flight, when I called customer service again for check-in procedures and asked about the suitcase dimensions, I was told that I would not be allowed to board with the suitcase of these dimensions. To avoid any issues before the flight, I had to purchase a new cabin-sized suitcase. I was told that I misunderstood the customer representative for my feedback with reference numbers 8982541 and 9059354. Due to the misinformation from your representatives, I had to incur the cost of two suitcases. I am requesting reimbursement for these expenses.