No problem looneymum, it's such a stressful time, but it does settle down...
Complete silence is an excellent tactic for several reasons. He no longer knows exactly what you're thinking, and so, can't plan his next moves accordingly. Also, by not communicating with him it sends out an insulting message to him. It is really quite dehumanising to be totally ignored. I know my x has found that more frustrating than anything I could EVER say to him!
The 'flaunting' wealth thing really strikes a chord with me. Over a year ago, my x's solicitor sent a letter to me, and the gist of it was that my x 'didn't want to have to go to court to order me back to the uk, but if I persisted in ignoring his very reasonable entreaties to do the right thing blah blah.... The letter stated in a really condescending way that 'my client's x lives with her parents depended on their charity and on benefits"!!!! It was such a horrible MOCKING letter.
But my solicitor was great. He reassured me that poor is not negligent. The support of maternal grandparents is seen as a GOOD thing, and, he's just put down on paper that he's left me in the position of having to claim benefits etc because he's not contributing!!
So, my solicitor wrote back saying that the two children were happily settled in to school, ballet, extra curricular and were enjoying getting to know their cousins and life by the sea and near the mountains in the community their mother had grown up in... but if his client felt he had a chance of winning, then see you in court where we will sort out maintenance.
My X's solicitor must have got that letter and said look buddy, not only are you never going to win a court order to have those children ordered back to the uk, but you're advertising the fact that you're not contributing anything to their welfare!!
Get a good solicitor, one with experience of these complicated matters. A few solicitors I saw, CAB provided one at one point, just to advise me, he hadn't a clue..