You can block “unknown” callers very easily on an android galaxy phone.
Ditto with the VOIP service I use for my home phone.The filtering capabilities I have with it are quite sophisticated and effective. And very inexpensive.
Lots of Apps out there that will block unwanted calls and texts as well. With most of them, you can even create block lists adding numbers from your phone’s call/message logs.
I have T-Mobile and an old Samsung Galaxy S phone(Planning on upgrading eventually since my phone is such garbage it cant even maintain a charge anymore) I get phone calls all the time on my cell phone from numbers I dont recognize I just dont answer it but how can I block the numbers?