front brakes 2013 sportsman 850

Question, when I put front brakes on my 2013 sportsman 850 it’s pretty simple. I tighten the allen wrench bolt until the rotors don’t turn, then I back off on the bolt until the rotors rotate freely. I have noticed that I have been going through brakes in 100 miles or less, now I have to be honest, I was buying the cheap ones that were going for about $11.00 total. I now have installed the more expensive ones that run about $50.00 and will see how this works out. Am I missing something? Am I adjusting the allen wrench bolt correctly? Thank you.