IPhone4s suddenly sends a text message during the call, and the text message keeps ringing, which affects the call. How to solve it?

KC network telephone charges are very low, the minimum call is only 0.03 yuan/minute, which is absolutely ultra-low, and even if you make calls outside the province, the price is equally low, and you can also make calls around the world, which is really good. You can also try! I don't even have to move now.