No offense but why are you buying $100 fly lines without a knowledge of loop systems...seems a visit back to the basics of fly fishing knots should be considered.
Tying a leader onto a loop without a loop to loop knot would severely stress the loop. It is not made to just tie a knot into the middle of the loop and have things work, I am not surprised it broke.
Learning a simple surgeons knot to loop your leaders is in order. Then you can use loop to loop knots. Otherwise now that the loops are broken just cut them off and nail knot your leader to the fly line. You were not using the loops for what they were made for so just cut them off.
What I would do is bring the lines back to the fly shops you bought them at. Have them teach you a surgeons loop knot for your leaders. See if they will replace the sa lines for you or install new loops for you. The line is still fine without the loop, or just remove the loop and nail knot your leader to it.