Thanks for notifying us here and being vigilant about spam messages.
This is the legit Samsung Care+ website. Notice the https://. (*secured)
For now, you can do the following, aside from not replying to text messages:
1) Block the number
2) Report number as spam.
My Samsung Store didn't know, coz I inquired 2X re Care+ and freebies, said not in their Store purchase package. I ordered anyway. Hindi nagpaligaya.. But I was given Samsung Powerpack upon phone release, and now Care+.. Keep them coming 😄..