blacklist my number

I am not getting any assistance, i reported ***** with the network that my numbers has been hacked and its being used for *****ulent activities, like to apply for credits and maybe other activities not sure what. I reported this matter since last year around October. the only thing i got was my number is being ported and that they cannot block the number because is prepaid. So now the person is continuing using the number for *****ulent. so what must i do to get the number blacklisted?