Not planning to quit, as I have had the service since 2001.
I did not know that it was a discontinued service, but am well aware of how the grandfathering system works.
When you sign up for any cellular service, you sign a contract.
This contract usually binds you to certain terms and policies, but in cases like this (and others) it binds the company to continue to provide otherwise discontinued services.
Originally, in 2001, I signed a 6 month contract for $25 a month. This was with a local carrier that used AT&T towers (Centennial).
After 6 months were up, they pestered me to sign up for a new plan, but instead, because I had read the fine print, I just kept making the monthly payment.
Even though that plan was no longer available, they had to provide it to me unless I breached the original contract somehow- which I didn't, lol.
Years later, AT&T bought Centennial, and part of the deal was that AT&T had to honor all past contracts that Centennial still had active.
I maintained that sevice until AT&T came out with the 10¢ a minute plan, which cut my bill (but also my monthly minutes) by 66%.
I kept my number, but switched to the new plan (GoPhone), somewhere around 2008-9.
Anyway, from what I see, the new pre-pay isn't that bad, but it is more expensive.
https://www.att.com/prepaid/
You and I are using the service for auxillary, and that is a small market that is probably not profitable.
Something maybe worth looking into is an emergency phone.
Basically a no frills, low minutes, no data set-up so that you can have an emergency phone in your glove box while traveling kind of thing.
I know that AT&T used to have that, for about $100 a year plus the device.
If not, then there is most likely something similar that is marketed for the elderly or otherwise in need of such emergency style service.
Let me look around and see.