Joke Collection Website - Blessing messages - How long will the content of the short message be kept?

How long will the content of the short message be kept?

Generally, the phone bill of a mobile company can be kept for 6 months, but you can't find the content of the short message you want, even through the court. The data it holds is only the number of words in a short message, with no specific content. Even the manufacturer who developed this project does not have this data.