Messages from AT&T: We will Lock Your Devise Soon.

Recvd 5 Messages on 9/24/21 from 5 different phone #'s, and 2 more today.  I have received many more but always blocked them.

"AT&T Free Msg: We Will Lock your Devise Soon.  Please clear spam messages.  Scan Now  >>a7Izq.info/ B5v5WOoDI  from phone #16574808659

and

9/24  #16574808515  B5HFtu4Xf7  --  #16574808699  B5JlxwtQgg  --  #1345831295  B5OnlmCxT3  -- #16026844994  B5TpTcD4BL

9/25 #12139524481  >>closch.info/   JOrhsGKzzg  

9/25 #19158082798  >>Kzd7.info/     9d84IE6v3c  (You used 95% of your data plan.)

Is this a spam?  How do I get rid of these and stop future messages.  I block them but I seem to get more.