To my knowledge, Microsoft provides Teams PSTN usage report in the Microsoft Teams admin center. You can view detailed information of display name and so on.
For more details, please refer to:
If the answer is helpful, please click "Accept Answer" and kindly upvote it. If you have extra questions about this answer, please click "Comment".
Note: Please follow the steps in our documentation to enable e-mail notifications if you want to receive the related email notification for this thread.