What can I do about a notice to vacate?

I live in Melbourne and yesterday received a notice to vacate my rented premises without a reason cited. When I visited the property manager, she refused to give me a reason. I believe this has to do with bullying from the other tenants (I have had my car vandalised recently plus my garden interfered with) I do have photos of one of the tenants holding a pot plant, as she would regularly come into my garden and move them. When I started to tell the property manager what was going on, she inexplicably became hostile and would not let me explain anything. I never received a warning, or told to change anything, no one called me and I am not been given a reason. I think the other tenants have been working on the manager for months to get rid of me. I am happy where I am so do I have a chance if I take this to the Tribunal? I've lived here for 10 years and never been late on my rent.