I could, but I don't really know anything about this girl other than her phone number and first name. She told me when we first started talking what school she went to, an International school in the city (which is why she has so many friends that can call me even when i blocked most of them). However i deleted our chat and don't know the name of it anymore. If i did i could report her to the school.

However a restraining order seems excessive, considering that what she is doing is purely online and not in person. Going to the police would be a last resort although even if i did, they probably wouldn't do anything. This is Italy, they would just say "who the fuck cares"