Pixel 5a on AT&T

Just got off the phone with tech support to find that att stopped supporting the 5a? One year old phone and I love it, but have to either sell it or change carriers?

Had trouble with SIM card abruptly after a year of use, figured maybe it's not a great electrical connection, so I ordered an eSIM card. Doesn't work. 4 att operators later and I find out they cut off 5a support in February and didn't tell me. What kind of company does that??