Constant outages by Network damage

I just started Xfinity Internet and now there has been network damage according to the outage details every other day. I read in another forum some one is most likely doing this damage intentionally by digging into the lines. My Internet has been down all day.My building is the only building this happens to out the whole complex.Besides this my Internet was hacked most likely from these guys upstairs who I've heard are "hackers" I turned off the wifi and used only my Ethernet but I also read that in apartments the lines are shared which causes security concerns which is strange because I have the firewall on but still get at least 800 attempts of someone trying to infiltrate my line according to the system firewall logs. Is this normal?