Sorry for bumping such an old thread but I receive tons of unknown calls daily and I do not know how to deal with them. Are the methods described in this thread still available? Who is still using them? I have found some services here https://celltrackingapps.com/suspicious-phone-lookup/. Have you ever used some of them?

Getting calls from unknown numbers can be frustrating. If you get them all the time, you might even want to avoid your phone entirely. A good way to counter the problem is to use a reverse phone number lookup tool.

https://www.novabach.com/who-called-me-find-out-whos-number-this-is-in-minutes/

Good