VOICE MAIL

are you using the built in VM or the app?

either way you go in and start deleting them? the one you must call in to you will need to listen to the prompts as to what button you must push to delete each message..if its the app then hold your finger on one of the messages you wish to delete then once its selected you can then start tapping other messages to include with the one you want deleted and do them in larger batches.