drain in back garden

[revlac]

Hi
We have 2 drains in our back garden one that we use and unfortunalty how the pipes run the other is the next door neighbours. This drain keeps getting blocked up every 2-3 weeks with their excrement, paper towels all mannor of things and at one point they had flushed 3 dead kittens down it. The thing is we have to keep unblocking it because it gets to a point where it smells too bad, its really awful.
Do we have any rights for this drain to be removed from our garden?