Hello Anita2509,
Welcome to the community!
I think everyone is rather fed up about getting SPAM and SCAM calls. However, most of them tend to show from spoofed numbers. That's why the numbers keep changing. That's also why some of the numbers may not be assigned when called. Unfortunately, there currently isn't much that any of the mobile providers can do to prevent them. Since the spammers/scammers use spoofed numbers, it is not possible to identify the true spammers' number. The numbers shown on caller ID do not belong to the spammers. They often belong to innocent, unsuspecting people. Unfortunately, there isn't much that can be done to prevent numbers from being spoofed. Even the RCMP are not immune to being spoofed (see here and here). Reporting those phone numbers do not lead back to the spammers/scammers. Any filter would block innocent customers from accessing their services, not the spammers/scammers.
There are measures put in place to combat these types of calls (ie Universal Call Block, STIR/SHAKEN etc). I also understand people expected STIR/SHAKEN to have brought those types of calls to an end. Unfortunately, it was never meant to block calls from spoofed number, it only identified them as Possible or Likely SPAM.
In addition, there are other limitations to STIR/SHAKEN. For example, the calls need to be end-to-end internet-based (see here). In addition, many of the calls originate from regions where the protocol has not been implemented (see here).
Unfortunately, I don't think it will be possible to rid the problem altogether. It is more or less a Worldwide issue -- with some Countries affected moreso than others.
Some providers may have other measures in place to reduce robo-caller SPAM calls (ie Call Control). However, some people rely on legitimate automated call services (ie Pharmacies, Doctors' offices, Libraries, etc).
Hope this helps 😀
Cheers
