I am not clear on what you want to do from your post:
"No setting that asks to unsubscribe ????", but this may offer you some options:
1. Go to: [https://web.vma.vzw.com]
2. Sign in to your account.
3. When you are on the "Verizon Messages" web page, click on (select) the 3 bars on the left of the red bar and select "Settings".
4a. If your intention is to "Delete My Account", select that option and read the explanation before continuing.
4b. Otherwise, click on (select) the 4th line "Manage Devices".
5. On the resulting "Manage Devices" screen, all your "Devices Registered with integrated messaging service" will be listed and you should find a "Registered Devices" line with a "Disconnect" option on the right of each line of the table.
I hope these options answer your question.