I have been a lifelong O2 customer. In 2022, I took out a contract, and it has turned out to be the worst decision I've ever made. I have spent years on the phone trying to get basic issues resolved. Since July 22, 2023, I have been trying to update my account after they replaced my phone due to a fault, switching from the S21 Ultra to the S23. Now, as I need to make an insurance claim in January 2025, I have been informed that my account has still not been updated—despite being assured that it would be done before the replacement and several times since then. As of today, I have made over 400 hours of phone calls to O2 and still have not resolved the issue. They raise complaints but fail to take action, escalate issues without follow-through, close complaints without addressing them, and promise call-backs that never happen. I've been paying for insurance for four years, but I can't use it because their customer service agents are the most incompetent I have ever encountered. The signal is poor or non-existent wherever I go. There are many other instances illustrating why this is the worst company, but I fear this message would exceed the available space if I included them all.