IKEA Jarvfallet Chair Making Noise

I purchased a Jarvfjallet model chair from IKEA and later bought another one due to my needs, mainly because of the 10-year warranty offered by IKEA. However, it is deeply distressing to learn that IKEA might be deceiving its customers. After assembling the second chair, I discovered that there were differences between the two chairs. I had chosen this chair specifically for its 10-year warranty. After using the first chair only four times, I noticed a sound coming from the mesh part of the chair when leaning back on it (a natural sitting movement). I contacted IKEA customer service, and the next day an "expert" named Ali K* came to my home. He acknowledged the issue, confirming that there was indeed a sound. However, he claimed it was normal and that there had been no complaints about this issue. This statement, coupled with the store's refusal to take any action on the grounds that there is nothing wrong, is quite shocking. Expert Ali stated that it was not a user error, and there was no hidden defect. However, there is no information in the product details indicating that the product might produce sounds. Considering the significant amount of 7,500 TL spent on purchasing the chairs, I request that my dissatisfaction be addressed. Otherwise, I would like to inform you that I will escalate the matter to the Consumer Arbitration Board and subsequently to the Consumer Court.