I think you can wait about 2-3 days and start again. It is very frustrating I know. This used to happen to me. I have an alarm clock and I started not turning it off when it woke me up, but resetting it immediately to the next time. If I turned it off? I'd often either drop off to sleep again, or I'd forget to turn the alarm back on even after re-setting it.

So I leave it beeping until It's fixed for the next time.