Hi there Andromeda
I am really sorry to hear about what must have been (and still is) a horrible experience.
You do need to act quickly to try to secure the return of the children. There is no presumption of residence with one parent or the other but it is correct that both of you will have parental responsibility which means you should have a say. You can seek emergency orders from the courts for the return of the children if they have been taken without your consent.
I am a family lawyer and accredited mediator based in Clapham Common. My firm is www.burgessmee.com
. If you'd like I would be happy to speak on the phone myself or arrange for one of the team to get in touch.
I really hope you are getting access to the right emotional and legal support. Let me know if I can assist at all.