File a complain to this authority about what are you facing and i believe that your issue should get resolved
https://www.citc.gov.sa
Hey there,
Sadly that's true any customer with STC is targeted by these fake sms even business and I'm talking about a personal experience so, if you want to stop it you can file a complain to this authority and these sms should get blocked
https://www.citc.gov.sa/ar/mediacenter/pressreleases/Pages/2018120401.aspx
Update: You can just file a complain to the website i mentioned above for calls too
https://www.citc.gov.sa/ar/mediacenter/pressreleases/Pages/2018120401.aspx
Just file a complain to this website
Just check your bank about it and call local authorites about it
You can susbcribe to STC or Zain if you hate mobily