What's your take on partying neighbors?

So, we live in an apartment building. 4 floors. The building housing contract says quiet hours are 9pm to 8am. The upstairs neighbors had a party on a weeknight. There were at least 15 people, sounded like more. We work hard and and usually in bed 9:30. At 9 they were loud so we called security and they were quiet for a little bit an then at 10 they were loud again and we called security again and it seems like they're quiet now. So my issue is, I always feel super akward and stressed out when I have to confront neighbors or deal with a situation like this. It really makes me anxious and worked up. So my question is. Do you let it slide where you live, is there some social leeway you give neighbors or would you do the same? We never party or really have social events at our house. So it's not like we're expecting the favor in return.