SIM card tray ejects but SIM card isn’t in tray

I keep getting the “no SIM card” error message. Each time I get it, I reset the phone and problem solved, but so annoying! It’s happening more and more frequently — like every other day — so I went to Apple Support which said to eject the card and put it back in ... which led to my current problem. When I eject, only the tray comes out. No SIM card enclosed. Has anyone else encountered this? It’s an iPhone 6 but it’s only 2 years old. (Apple Store messed up my old one so they gave me a new one). I’ve got the latest OS for a 6, which isn’t 13.