Turkcell Charged Me High Termination Fee One Day Before Commitment End

I was using a 50 GB package with a 12-month commitment on my Turkcell postpaid line 0554*****12. My commitment was supposed to end on 09.08.2025, but on 08.08.2025 at 14:40, I switched to another operator. Following this, I was billed a total of ₺1300.59, which included a ₺650.05 early termination fee, ₺21.50 in taxes, and an additional ₺629.03 usage fee. I carried out all my transactions through online customer service. Even though I switched just one day before my commitment ended, I was never informed beforehand about any early termination fee. I only received the billing information via SMS, with no warning that such a fee would apply. In the past, when I changed operators close to the end of my commitment, I was never charged such a penalty. I do not think it is reasonable to be billed such a high fee just one day before the contract ended. When I called customer service, they only confirmed that the fee was charged but offered no solution. In my research, I also found many similar complaints on this matter. To avoid issues with my record or legal processes, I made the payment. However, I find it unfair to be forced to pay such a high termination fee so close to the end of my commitment, and I request the cancellation and refund of the early termination fee and the related taxes.