"Then I went to VZW on my computer and printed off the call log that they are calling. Then I started calling the numbers telling them that the local police department would be visiting them soon because they were involved with a felony. I don't know if it is true or not but I said that they stole a $500 phone which made it grand theft and I would press charges against everyone I could find that was involved if I didn't get it back."
It's not, and you might get in trouble with the local police for harassment. Put it this way, if someone calls you on a phone, do you know if that phone is stolen? I sure have no idea how to find out if someone is calling me on a stolen phone.
Now, if you can prove the person on the phone was an accomplice to the person who stole the phone, yes. But explain how that will happen.
Just saying, as someone who has some experience with the law (very soon to be retired FLEO), I would be careful about threatening people over the phone with legal action, when legal action is not an option.
Another thing to watch out for....
Going to an address where you see the phone at. What if the GPS is off by one house? (Consider they can be off by about 20 feet, and a condo is a great example of the location being wrong.) I know you come to my house and threaten me, you will have a SIG pointed at you faster than you can say DROID. And believe me, in most states, threatening someone at their front door, does not require a badge to pull a gun and point it at you.
Yes, they may not have the legal recourse to fire, but you cannot threaten people at their door without having possible problems. Heck, he (or she) may just be the type to slam you down and hold you till the police arrive. SO BE CAREFUL out there.
A phone is not worth ending up with a legal or even a possible civil charge against you, or you ending up in a hospital with a broken bone.