Do nothing like yet says, if he gave a damn about you at all he wouldnt have cheated and i think the voice mail is just his way of calming his guilt (ha)or more likely reminding you of him and tossing his ego with pleasure at your pain, change your number so he cant reach you will smack his ego up his darker sun dont shine there anatomy region dont let this limp dick torture you, he will cheat on you again because if you went back to him he cant respect you for it just use and abuse your emotions
Keep the strength vamp
A mistake is always forgivable, rarely excusable and always unacceptable.
Robert Fripp