My provider says that all deleted text messages are gone. If I want records or my previous text how can I access or obtain them? Do I have to take a legal route? If so is this hard or expensive?

Unless they are stored on your phone, its unlikely they can be recovered.

A friend of mine recently learned than unless the text message is still on your phone, it cannot be retreived. Additionally (at least for her phone and carrier), there is no way to download the text messages from her phone to a computer to generate a print-out of the message. The only thing you would be able to do (depending on your carrier, probably) is obtain a printout that says when you received a message and from what number. So you would get something like this:

Text message sent from:
123-456-7890; 3:00pm; October 8, 2007
To:
321-654-0987

Something like that.