I don't like the sounds of this... I used SMS Backup and Restore. I thought it had backed everything up (to Drive), but the backup only went a few months back (and maybe overwrote the older ones?). I was looking for about 5 months more worth of messages... I'm guessing it will only back up a certain amount per session. I suppose if I had to do it again, I'd focus on backing up messages from particular people I wanted a record of. If they're gone, all is not lost. I have a pretty good case, I think.
My provider told me they have zero access to text messages, is this the case? I thought they'd have them, even if it meant hiring an attorney to subpoena them.
Thanks for your input.