1. Do NOT communicate a "deadline" date to her. If you give a wayward spouse a deadline of "X", they will inevitably continue to waffle and cake-eat until Day "X minus 1", at which point they will promise you the moon and the stars in order to get you to call off the dogs. Your deadline should be an INTERNAL one, for your own emotional health (it really helps to know that you've given it a time limit of, say, 3, 6 or 12 months). All you should tell HER is "I will not wait forever," or "my patience is not limitless," or "I hope you'll hurry because each day I lose a little more of my love for you."
2. You need to stop paying for her cellphone immediately. You shouldn't be using the family's finances for her to conduct her EA. She'll be livid (who cares -- she's running away from you and cheating on your now anyway), and she'll merely open her own, but you will have established an important boundary.
