uk and usa store - diferent games

I have £7.87 in my ms account but when i change the console region to usa my bank card and uk balance disapears, is it possible to sign up for a pre-paid usa card and add that to my account so i can buy usa games wich are not available here in da uk?

 

You should of just had your card on it, then changed region and bought it.

Wait for it to download then change your region back.

 

My card is on my account but like i said as soon as i change region from uk to usa my card disapears

 

Hmm... thats strange it worked for me when I bought Watch Dogs.