Lots of different approaches
but the result is what counts. Your decision should be based on what will most effectively stop them. Fighting back works only if you are sure you can win (and then there's the risk that they will be so pissed at you that THEY will tell on you!). Bashing someone with a metal pipe is just plain stupid (sorry), as the stuff you'll face in prison as a result will be far more intimidating and dangerous than these guys.
Telling the authorities is not 'tattling', it's self protective. And they will stop it.