Help Phantom alarm keeps going off fter deletion

[kilinrax]

Festive greetings to everyone. I have a problem with the alarm on my Nexus 7 v2, which I've tried to switch off over the holidays, but it keeps going off every morning. This is what I've tried so far, in order (one per day):

• Setting the alarms to 'inactive' via the sliders
• Deleting the alarms
• Clearing the data for all apps that might still have them cached (Clock, Timely, Dashclock, Sleep as an Android)
• Deleting Timely and Sleep as an Android
• Setting the alarm volume to zero in Clock
• Disabling Clock

I have read through the two other threads I've found here describing similar (though not identical) issues, and am at a loss as to what else try. The alarm extension for Dashclock still shows that the alarm is set, though if I click on it to open Clock it says there are none defined.

Please can someone help; I'd been hoping to catch up on some much-needed sleep over the break, and this is driving me spare. I don't really want to have to factory reset the tablet and fence it on eBay, but short of switching it off and leaving it in a soundproof box each night, this currently seems like my best option.