How do I stop getting "Use verification code for scholar-web-app authentication" message on iPhone?

Hello, from more than a week i suddenly start receiving messages with the following content "Use verification code xxxxxx for scholar-web-app authentication." I tried many times to block the sender but there was no effect. I receive these as a messages on my phone and on a viber. I contact my provider but they said that they eventually can block all my incoming calls, but than i cannot use my phone. Could tou give me some redolution ?

Best Regards !

[Re-Titled by Moderator]

Original Title: Msverify