I texted them asking who they were, and got an immediate reply saying
"Thanks for the message. Configure your number's SMS URL to change this message.Reply HELP for help.Reply STOP to unsubscribe.Msg&Data rates may apply."
I replied "STOP" and received
"You have successfully been unsubscribed. You will not receive any more messages from this number."
I texted them asking who they were, and got an immediate reply saying
"Thanks for the message. Configure your number's SMS URL to change this message.Reply HELP for help.Reply STOP to unsubscribe.Msg&Data rates may apply."
I replied "STOP" and received
"You have successfully been unsubscribed. You will not receive any more messages from this number."
Yeah, that won't work, but from what that message says I would make sure you check your next phone bill because i have a feeling you are going to get hit with a big fee for texting them back. Even if you don't, they now have a live number to sell to other scammers so get ready for a ton more texts. If you don't know who it is, do not text them back, just as you are not supposed to reply to spam e mail.