I was broken up with that way once. We were in high school. So, I'd say that, yes, there are people, immature people, who use that as a way of breaking up. Really sorry if that's what's happening to you. I'd say, if it's really been a while -- like, a couple of weeks -- just leave the person a message saying "If you want to contact me to tell me what's up I will listen, but I'm assuming we're over and am going to start working on moving on."
Me, 30ish bi female, been doing solo poly for roughly 5 years. Gia, Clay, and Pike, my partners. Davis, ex/friend/"it's complicated." Eric, Gia's husband. Bee, Gia and Eric's toddler.