I wont go into much but prove they are bullies I got a domain in 2007 ( 3 years before Facebook came to the UK and trademarked ) and was live in 2008 with 5000 users on a dating site. now gone to trademark for a app and now letters and lucky got a IP lawyer on board
No surprise here. FakeBook is a bully like most other big corporations including Darth Google, Maleficent Microsoft, etc. The unfortunate part is that they have the deep pockets to make their bullying a success in many cases. Good luck with your effort.
Its unfortunate, but you're experiencing a very common problem, Might makes right. I'm an attorney in the states and one of the first things you learn, the hard way, is that large corporations and governments can out spend most people and most smaller businesses to get what they want. Unless you have deep pockets or a wealthy relative, its just better to take whatever marbles you have left and walk the other way. Sucks, but that's life.
What is your mark? Just because you had a mark first doesn't mean you'd have a case anyway. If Facebook was operational and globally recognized before you made the mark, they have a clear case that you infringed on their mark because you clearly knew about it.