Oppo A55 Lag Problem

I have been using the Oppo A55 for about two years, and I’ve had the same issue the entire time. I’ve complained before, but no one has paid attention. The problem is that the phone lags excessively—for example, when I open recent calls, the list takes 3–4 seconds to update, which has caused me to make many wrong calls. The message list also takes 3–4 seconds to load. Even after software updates, the performance has not improved at all. Switching between open apps is even worse; every app restarts as if it’s being opened for the first time. The phone is incredibly frustrating to use. I’ve seen others with the same complaint. Please pay attention to us and help.