2G free phone replacement

Unfortunately, that is the condensed version, HeavenM.  It has taken a significant amount of time across multiple visits to multiple stores and several calls to the T-Mobile 800 customer service number.  After four months, we are no further along than we were when we initially received the text at the start of October.

I have still not been able to get a screenshot of the phone, but here is the wording from the text message:

T-Mobile: Heads up!  As we continue the work to advance our network, we will be retiring our 2G network on April 2, 2024.  To continue to be able to use your T-Mobile service, including the ability to make 911 calls depending on your location you will need to replace your device.  Get info here: t-mo.co/46rvrsl

Your message above is the first time that we have heard that we could lose our accounts.  Given the age of the phones, are there any compatible phones even available?  I am not an expert with technology, but, if I understand the instruction manuals that came with our phones, we will need to take the SIM cards out of our current phones and put them in new phones.  However, do the old SIM cards that came with the T-Mobile phones that we purchased in 2007 and 2012 even fit in the phones currently sold?

As I mentioned above, we do not know why T-Mobile is treating us this way.  Everything seems so difficult, it feels like T-Mobile just wants us to give up.

I want to thank you again for taking the time to respond.  If you can give us some advice on how we can keep our T-Mobile accounts with our current T-Mobile plans and also what a compatible device would be for SIM cards from 2007 and 2012, I would be grateful for the assistance.