6months ago when my husband moved out he bought my 9yr old a mobile phone, I wasn't impressed, its too young and she is still pretty much with either 1 of us 24-7 so we can talk to her (or vice versa) on our phones. But of course the phone stayed. Just lately when I have rang or sent a text and my daughter wants to speak/text me he refuses saying that he bought the phone and it is for contact with him and only for emergency use with me !!!! what a situation to put children in!! The other day my daughter sneakily sent me a text without him knowing. I am appalled that he has in effect caused our child to be deceitful and for what reason, it also doesnt help the children to feel secure in the knowledge that they can happily talk/text mummy anytime. There are other things he says and does that I feel puts my children (I have 2) under emotional stress, does anyone know if I can do anything legally about this?

Hi, I'm so sorry to hear about this. I can't offer any legal advice, but I'm familiar with this sort of situation, so can pass on what we did...
My hubby as NRP bought a pay as you go phone for his daughter (outright, so no monthly bills). He periodically gave her top-up vouchers so she always had credit for texts. When she wanted to speak to him, she would ring him on his mobile then hang up, so he could call her back (no cost to her).
This has always worked well - they get to talk when they want, she can text him, it doesn't cost much (one initial outlay for the phone and the odd £10 credit. The phone is then for the child to keep in contact with both parents. Also, the child when young, isn't tempted to rack up huge bills, thus making the problem worse.
I know the difference is that my hubby wasn't creating problems and being nasty about it all and its a far deeper problem for you than just a phone situation - I'm so sorry for you on this one.
If your ex is still being a pain and the phone is as I suspect on a monthly rental, how about suggesting a pay as you go phone as a Christmas gift from whoever, with top-up vouchers from the family?
Good luck xxx