Maybe this will help a little. The FCC is now approved to enforce rules about robocalls and text messages from International sources. They are now free to take legal and technical action to block this. Phone carriers are in the process of implementing "SHAKEN/STIR" which are technologies and protocols to enable authentication of the originator.
https://www.cnet.com/news/fcc-adopts-rules-to-go-after-international-robocallers/
Until all this gets sorted-out, my phone forwards all unanswered calls to the FCC hotline 1-888-225-5322. Since doing this, all my robocalls have stopped dead in their tracks. The "cash loan" texts are slowing down because I set my phone to not automatically download MMS and I delete them before reading them. This way, the sender never gets confirmation of delivery.
Ray
https://www.cnet.com/news/fcc-adopts-rules-to-go-after-international-robocallers/
Until all this gets sorted-out, my phone forwards all unanswered calls to the FCC hotline 1-888-225-5322. Since doing this, all my robocalls have stopped dead in their tracks. The "cash loan" texts are slowing down because I set my phone to not automatically download MMS and I delete them before reading them. This way, the sender never gets confirmation of delivery.
Ray