How to block unwanted number - Nokia C3 Cell Phone

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I wans to block unwanted callers from my alcatel 980Yf00

1. The first thing you can do is to make sure your cell phone number is unlisted. This is a simple step but it's the first step in keeping unwanted calls from your cell phone.
   
2. You can unmask the Caller ID on blocked incoming calls, obtain the phone number, and in some cases the name and address, of the "anonymous caller" by using a service called "TrapCall." You can also listen to your voicemail over the internet.
   TrapCall allows you to unmask numbers, record your calls, voicemail transcriptions, block unwanted callers, and gives you caller id for your cell phone. See resource link.
3. Register your number with the "National and State Do Not Call Lists." The National Do Not Call list is run by the Federal Trade Commission and you can sign up online at the resource link below.
4. Even after signing up for the "Don't Call List" and getting that unpublished number there are still those times when the telemarketer finds a way to get through. You can also get unwanted calls from ex-boyfriends and ex-girlfriends'. These people have your number from your previous relationship. You don't want to change your number, but a few over-zealous ex-mates may not go down without a fight and will continue to call after you have told them to stop! In this case, you'll need a call blocking device. These devices allow you to control who calls you, and gives you the ability to permanently block their numbers. See the resource link at bottom of article for a list of these devices.
   
5. Set up an account with "Reverse Phone Detective" service in order to find out the Unknown numbers that appear on your caller display. This will allow you to see who and where the number is coming from. Check the resource link "Reverse Phone Detective" below.
   
6. 
   

Don't rely on your cell phone provider to block unwanted calls for you. For some inexplicable reason, most carriers do not provide you with the ability to block unwanted callers.

My best bet is to go with the google voice number(you can do a lot of things besides blocking unwanted numbers and its free) ..

here is the link to find more information about it

https://www.google.com/accounts/ServiceLogin?service=grandcentral&passive=1209600&continue=https://www.google.com/voice&followup=https://www.google.com/voice<mpl=open