It sounds like you got some defective thread, you should take it back to where you bought it. My Aurifil thread has always been great. One time my sister bought a package of pre-wound bobbins, she thought they were the wrong size for her machine because if kept breaking, she gave it to me and I tested all 10 spools and the thread broke like it was 100 years old, it just broke - I couldn't even use it for basting. Sometimes they get a defective batch.