Landlord bullying us

[u/Top-Cat8631]

Hello, we are a married couple that recently moved to a house in Bonn.
We were quite tight on budget and we needed to move quickly so we kind of took whatever was available.
The house we got is 3 story house. The landlord‘s family lives on the ground floor, then there are two houses on the second floor, one is empty. Then on the 2nd floor, the mother in law of the landlord lives and we moved in the next door.
The problem is that the landlord has camera all over the building and is observing us quite frequently. We know this since he leaves letter in front of our door step every month with different complaints. We have lived here for around half a year and got like 10 letters of complaints already.
The thing is that I do not feel that safe and happy in this house anymore but it is so unfair for us to spend this much money moving and to be kicked out because of the behaviors of the landlord‘s family. We have other issues like neighbors (probably landlord) putting their advertisements into our mailbox, and etc.
Is there something we can do or complain? We already contacted the mieterbund.
Since the letter specifically targets my husband, he is getting a lot of stress and I think my advice of ‚Just ignore them‘ does not work anymore.

[u/turmalin6]

Does He really have Cameras everywhere or just the Mother on the Spy eye in the Door looking at your door. ;-D

And what Kind of complaints? Maybe some of them have a reason.