Text message transcripts

I am trying to get my text message transcripts from my phone number and I keep hitting dead ends. On the Xfinity mobile app it only shows the date, time and number but not the actual context of the message. The customer service number wasn't able to get it and sent me over to the legal office. They said that they do not keep transcripts but I know that isn't right. I need help getting my text message transcripts please.