Turkcell Superbox 500 GB Slow Internet - Constant Freezing For Months

I have been using the Turkcell Superbox 500 GB package for about 4–5 months at my address. During this entire time, I have experienced low speeds and constant freezing at all hours of the day. Since I work from home, internet speed is very important for me, but I am absolutely not satisfied with the service I receive. I contacted customer service many times and a fault report was created. I was told that there was a signal issue in the neighborhood and that the problem would be resolved, but I was not given any information about when it would be fixed. I am paying ₺1,811 per month under a 12-month commitment, and not being able to receive proper service for such a high price causes significant inconvenience. Despite submitting many requests, the issue has not been resolved. I now request that my grievance be resolved and that I be granted the right to terminate the contract without penalty.