get a new cell phone plan, unless you want to keep paying his bills.
i still don't get how exes can go to friends if you have to deal with missing and longing...that is not what friendship should be about, especially if coming off romantic relationship.
did you give thought to maybe he is not as comfortable with being friends as you think you are?
i believe some exes can be friends, even if it isn't for me, but imo, it either is or it isn't. waiting it out, overanalyzing, being soulmates; you just can't force it.