What do you do on the lead up to Christmas if your children aren’t allowed to see you and they sit under the immobilising spell of a hate campaign waged against you by your ex?
In the short term, there’s not much you can do to be honest unless you are prepared to make a very disruptive noise. If your ex is unfairly controlling the contact they have with you, there’s always the choice of taking them to court to have a judge certify what your visitation rights are, but even then, a vile and spiteful ex will probably ride roughshod over it until they are forced to do otherwise. Also, that’s not going to produce a positive result before Christmas.
In the short term, any noises you make to try and see your children may well antagonise the other parent and it could actually make things worse for the youngster.
There are always routes through the barricades however and it’s your job to find them. Find an empathetic relative from the other side who can deliver a message, or go through school perhaps, maybe even just write an old fashioned letter and have it delivered to a neighbour or trusted friend. Pour love on your children via any means and know the malevolent parent will probably pay the price for their unpleasant behaviour; karma has a way of settling things eventually.