2G free phone replacement

Thank you very much, HeavenM, for taking the time to respond to my question.  I appreciate the information you have been able to share. 

We have two T-Mobile phones (one from 2007 and one from 2012).  The T-Mobile phone purchased in 2012 received the text, but not the T-Mobile phone purchased in 2007.  I have not been able to figure out how to take a screenshot of the T-Mobile phone that I can upload to my computer.  In summary, the text informs us of the end of the 2G network and ends with a website address.  Since the phone is so old, we used our computer to navigate to the website address (https://www.t-mobile.com/support/coverage/2g-retirement).  At the bottom of this webpage, it states that: "T-Mobile has communicated with all customers who have a device that relies on 2G, and these customers received an offer for a free device upgrade to ensure they do not experience service interruptions during this transition."  We then printed this website page and took it to multiple T-Mobile company stores after identifying them on the T-Mobile website. 

At one store, the associate informed us that it is not the "correct" text message for this offer and the store manager then went into the back.  At another store, we were told to buy new phones and get new plans.  One call to the T-Mobile 800 number resulted in a request that we mail our two phones to T-Mobile.  The 800 number representative offered to send us a mailing label.  Since this sounded highly unusual, we did not mail our phones to T-Mobile.  Another call to the 800 number ended with a promise for a supervisor to research the question and respond to us within 72 hours.  That was almost a month ago and we have not heard any more.  

As I noted in my initial post, "my family uses two 2G phones on the Gold Rewards legacy pay as you go plan".  Your message is the first time I have been told that prepaid plans (such as the Gold Rewards legacy pay as you go plan) are not eligible for this offer.  That is not stated on the website above.  When we provided our T-Mobile numbers and PINs at the T-Mobile stores, they looked into our accounts on their tablets, but did not tell us about this restriction. We do not know why T-Mobile is treating us in this manner. 

What will happen to our telephone numbers and phones in April?

I want to thank you again for taking the time to respond to my post and am grateful for any additional information you can give me about how my family can keep our two T-Mobile phone numbers with our Gold Rewards legacy pay as you go plan.