Petz Hamsterz2 for Gameboy advance?

[housemomof9]

I have made it all of the way to month 5 and still dont have enough to buy anything at the pet store, but what I really want is treats, when I enter the store only hamsters and cages are available. How do I get treats?
I have already tried to look it up online, but since it just came out in Nov. of this year, there are no hints, cheats or tips available. I am trying to help my 6 yr. old. Thanks!