We bought our 12--y-o SD a cell phone (because BM demanded that we did-- she's latch key) and we got her on a plan that locks us into a two-year contract. Then BM went out and bought SD the latest iPhone (or I should say BM's boyfriend did) and told SD not to tell us!! So SD (whom I get along with very well) lied about it to me and her dad for weeks. BM motive was to be able to communicate with her directly without having to go through us. We are in a custody battle and BM is forever manipulating her daughter to get information about her dad's job, my job, if her dad and I ever get into a fight, etc. etc.
So, we have restructured her phone use to be twice a day to call and TALK to her mom and no texting in our house. SD was compliant with the rule... as she always is. But, her mother refuses to answer the phone when she calls (because she doesn't actually WANT to talk to her, she just wants to win this sick game she is playing) and told 12yoSD to break the rule in our house and sneak her phone in her room to keep texting her!!! 12yoSD is so twisted up she can't even think straight, and I am violated regularly in my own house by SD's prying, but she doesn't know she is doing anything wrong. There is no reasoning with BM. Trying to talk to her went out the window a long time ago. We didn't punish SD. I feel like that would be displaced.
Has anyone dealt with anything like this? What do I do?