Annoying Neighbours

I live in a 2 story unit, that has a front and back yard and a driveway which i have to share with my neighbours who live below me, i haven't had any real problem with other neighbours Ive had, but the ones i have now are very very annoying.

They hadn't even moved in telling me that they no longer wanted me to park my car on the grass so the children could play in the front yard, (we have a backyard as well) i said no as the boyfriend has been parking his car in the driveway and i didn't want to get caught in front of his car and have to ask him to move it.
Her asking me to not park on the grass has been happening for around 4 weeks now. I said i would try parking on the driveway and see how it goes. As well as my car my nephews car is parked in the backyard.

On the weekend it was pouring down rain and he had parked his car behind mine as well as there being another car, i wanted to go out that day but to do that i would have had to walk down in the rain to ask them to move the car and wait, all the time getting wet.

When i got home yesterday she was at the front door again asking me to not park on the grass, i have moved my car to a different spot on the grass so that the children can run around on most of it.
This time she told me that i had to move my nephews car and that "she" wanted it gone by the weekend, i said i would ask him to move it but i don't seen it happening.
Then she came out with that "i am not supposed to park on the lawn as the estate agents told her that" telling me that i could go in her place with her so we could ring the real estate agency, i ended up walking away and rang the real estate agency myself to find out what where i stood on all this.

It seems that i can park on the grass, and that i am to have 24 hours access to the driveway being able to get in and out whenever i want.
The real estate person said that she was going to contact the people that live below me and ring me back today, i haven't heard anything yet, but will ring back later if i don't hear anything.

Now i know though where i stand and the next time asks me to not park on the grass and I'm not supposed to, i will shoot back with you are not to hinder my entrance to the driveway which you have been doing and tell her to pull her head in.
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