Dear [Name/house number/property name],
I am writing to complain about a nuisance caused by my neighbour [name] of [address].
My complaint is that this neighbour [describe nuisance in detail].
I have asked my neighbour to stop this behaviour on [number] occasions, but they have refused to do so.
This level of disturbance is unacceptable to me and is causing me a great deal of distress - therefore I would appreciate your help to resolve the issue.
I look forward to hearing from you soon.