What happened with my phone???

I have a flip phone, and when I was told there would be a 15 to 20 minute wait to talk to someone at Comcast/Xfinity, I plugged the charger in. I listened to their @##$%@$@#$ every-other minute spiel for maybe 15 minutes and then my phone went beep beep! and I lost the connection. It was the phone, not noise from the Comcast connection. The charging had been working and when I unplugged it was charged better than before. I did speak into the phone at least once, to say "Shut up, bxxxx!"

What made my phone do that??????

tia
las