Englishee is Dippicult, part 2

I have this recurring problem with my cell phone here, where it will spontaneously turn off, usually at the worst possible timing - mid text message, mid phone call, or the worst, middle of the night. I say the worst, because in our technically-groovy day and age, no one uses an actual alarm clark anymore! (do they?) I use my cell phone as my alarm, so it stands that I have been late to work a total of 4 days since I arrived in Korea, and I'm beginning to worry that the excuse "my alarm didn't go off" is becoming a bit hackneyed... and probably suspicious. Especially since it didn't dawn on me until now that 'my alarm did NOT GO OFF' is a STUPID ENGLISH PHRASE. How could I have missed this one? When every day I am so careful to use simple English words and speak at a rate 3 times slower than usual, how could I not realize that in most languages, 'not go off' equals 'stay on'???

I feel like an idiot. All this time I've been saying "I'm sorry, my alarm didn't go off" and they've been thinking, "Yeah, so why does that explain why you're late?"

Is this why the majority of my students have given up trying to learn English?