Did someone in your family already get the axe? Only one is allowed per family,not sure if this is the case for you.
Also, there is a bug with the axe where it just poofs and even with cheats you cannot keep one. It happened to me twice with two different families in two different games. My Sim would obtain the axe and it would be in his inventory until, he travels to Egypt, once he has gone to Egypt, poof, it's gone.
No way of getting it back, the spot in China it's kept in will be empty and if you use the cheat to get it through the buy mode, it will just poof again.
If the above is the case for you, I feel in this case, until EA gets a fix for this, its okay to use "testingcheatsenabled on" and using the shift key and clicking on the item you would normally smash with the axe. Considering as my Sim went through the trouble of getting it to begin with, he/she should be allowed to continue to reap the rewards from it.
Hopefully some of this information helps!
Lisa