That must be very frustrating! Try the following suggestions:
Make sure that your alarm clock is resting on both of its legs on a flat surface.
If your alarm clock is on a flat surface and it is still tipping over, you will need to tighten the alarm clock legs by following these directions:
Using a standard flat head screwdriver, remove the black battery compartment cover, which is located on the back of the alarm clock towards the bottom between the alarm clock legs by lifting gently on tab with the screwdriver. Remove (1) "AA" battery from the battery compartment. Set battery aside.
Remove the three small silver screws located at the top and both sides of the back cover using the #1 Phillips screwdriver which is in the iFixit toolkit. Remove the black back cover of the alarm clock by gently pulling upward being careful not to disconnect the wires which are attached to the back cover.
Locate each alarm clock leg hex screw which are located on the top of each post of the alarm clock's legs towards the bottom of the alarm clock. Using needle nose pliers, tighten hex screw onto post of right alarm clock leg. Using needle nose pliers. tighten hex screw onto post of left alarm clock leg.
Replace the black back cover of the alarm clock by gently placing it within the gold metal casing of the alarm clock. Line up the screw holes with the holes on the black cover. Using the #1 Phillips screwdriver, replace the three small silver screws on the back cover.
Good luck! Hope this helps!