What did i do wrong???????!!!!!!!?

My girlfriend has escaped from her cage twice in the last month, she heads strait for a grocery store all the time like the cat food i give her isnt good anymore, I tried beating her a bit and told her that only reason she tried to escape was because im 35 years older. I dont know what to do, i spend all my money on the cat food and the buckets for her to excrete her bodily fluids so i cant buy a huge padlock, please give me some suggestions, i really need some.