Verizon wireless text messages availability

I am having a very difficult time trying to find out how long Verizon keeps the contents of text messages on their inhouse servers.

This case involves a difficult divorce and the contents of text messages could prove alot.

Everytime I call Verizon Wireless, I get a different answer as to how long they keep these messages for. Of course, they won't allow me to speak with someone in their legal department to get this general question resolved.

My plan is to file a subpeona but before I do that, I want to know how long they keep text messages are for. I will file a subpeona if I can get messages for at least a year but if they only keep messages on their network for only 72 hours, that will not be enough for me and the subpeona will be worthless

Can I get a straight answer from anyone.

Thanks