Unable to change billing information to current region

Firstly I'd appreciate any helpful suggestions to resolve my problem.

iTunes wont allow me to change my billing information or region for that matter. If I can't make new purchases without making use of my current credit in another apple iStrore, why can't I forfeit the amount (it's only one peso), and why can't iTunes consolidate credit associated with a single account regardless of the region I first bought a product?

I tried googling my question, but all suggestions pointed to getting a new apple account every time you move to a new country. That made me very sad, I just wanna buy stupid apps for my ipad('cause it's kinda useless without apps), why is it so hard? I'm pretty sure giving birth is not this frustrating. ;'( :'(