Stop telling her what to do. You can't force another person to do anything. But what you can do is state what you won't tolerate. Start stating your boundaries.
Example: I know you were talking to him on Sunday and Tuesday, I will not live in an open marriage. Example: I know you were talking to him on Sunday and Tuesday, I won't be disrespected in this M. Example: I know you were talking to him on Sunday and Tuesday, I don't agree with your actions. I won't share my wife with OM.
If you know of consequences, you can follow your boundaries with them. Butt, IMO, one of the hardest portions of DB, is holding the WW spouses the the consequences presented. So don't state any consequences until you are ready to hold her feet to the fire.
Example: I know you were talking to him on Sunday and Tuesday, I will not live in an open marriage. And if you continue talking to him, I will file for D. ( The next time you catch her talking to him, you have to file for D or your consequence, become a moot statement)
You have a right to check the phone bill, she can get mad all she wants.
Let's look at that scenario logically: Is there anything wrong with looking at a phone bill: NO So if a person is getting mad because a phone bill is being looked at, they have the problem. Don't let her make you feel guilty.
Great job on telling her to file for D.
Stay calm, as calm as you can in this storm, it will pass.
M:36 W:36 T:11 M:10 S16, S12, S9, S4 BD:06/28/17 OM confirmed 07/20/17 Recon the M 10/29/17 Working hard:2gether
Onward and forward
This process is not a sprint it's a marathon! Patience, Patience, Patience.