Thanks for all the advice and just to update everyone.

I "had a word" with them tonight and got an apology for the photinia and one
of them came round and re-attached my trellises for me! So, I'm much
happier!

It is their wall btw, so I'm aware that I had no legal grounds, however, it
did only seem polite to let me know what they were going to do and no need
to burn my shrubs at all!

All the best, Eleni.