People parking in my spot

I am so freaking tired of coming home at night and finding the someone is parking in my covered parking spot. These stupid little bitches always do it when I come home and night and it just happens to be raining. And these mother fuckers have like 6 cars they take up all the extra parking spaces by my apartment. So last night I wrote this bitch ass a note saying
Hey dont park here. I am tired of coming home and your car being here! If ya park here again I will have your car towed!!! haha 
So they better not park there ANYMORE!
It is not my fault you guys own two trucks like three or four cars, and the apartments only assign one parking space for every apartment UGH!!!
I just hope they don't do something to my car or come banging on my door or something. Its scary enough I pretty much live on my own. I don't want to have to worry about people harassing me
so it is fair that I have warned them saying if they park there again their car will be towed right?
this stupid person has done this like 5 other times I think I have been kind enough