You are not in a good situation Martin. But any action will require proof or evidence.
I have a couple of these (see Below) from ali Express. – £20 and you will spend andother £7 on an xsdc card.
The software and control isnt great but good for the price. I ahve one on my drive and another pointing at my Hedgehog feeding station.
KERUI 3MP 5MP WIFI IP Camera PTZ Control Outdoor Two Way Audio Human Detection Auto Tracking
Just do a search on Ali Express for that.
You have to be careful you are not pointing the camera outwith your property.
Try making an appointment with your Citizens Advice and go from there.
You need to keep yourself legal and have the ability to protect yourself.
There are organisations that can help.Citizens Advice will help you.
Mostly the only thing the Council can offer is Mediation. But usually conflict is beyond reconciliation.