If the restricted calls are threatening, or dangerous, or harassing in any way shape or form, you may need to involve the police. They, of course have the authority to look into any phone calls, restricted or not and get the information they need.
Contact your phone carrier, and see what they are able to do. Your cell phone and landlines may have some security features available that you are not aware of to help you trace a restricted call, or even block incoming calls that are not directly from your contact lists. If you have tried this route, and reached a dead end, then there are other steps that you can take to trace a restricted call.
One option is to hire a private investigator. There are many online sites that let you post your request for help in tracing your restricted calls. After you have posted your request, you will receive bids from different consultants, or agencies. They will tell you how much the trace will cost and how many days they will require to complete the trace. Many of the bidders will have ratings and customer reviews for you to look at before you choose which bid you will accept. The bids ran anywhere from $300 – $1500 for the tracing of one restricted phone call.
There are also tons of online sites such as reversemobile.com, or using Reverse Phone Lookup Directory like reversephonedetective.com to get the information you need. Some agencies charge a small fee, others offer free information up to a point, and then require a fee for additional information. Each phone number is supposed to be linked to a name and address, and potentially you may obtain this information through any of these sites. Be careful which company you use, and be careful with the actions you take after you obtain your information.
If the restricted phone calls are a constant bother and annoyance to you, then simply don’t answer those phone calls! If they are prank calls, or sales calls, most likely they won’t even leave you a voice mail. If it is someone who truly needs to speak to you, they can leave a voice mail and a phone number to call back. Caller ID is one of the greatest, most useful tools that our cell phones and home phones contain. With it, we are able to choose who we communicate with, and ignore all the ones that we don’t.