i have 50 dolars
i have 50 dollars on my account but i cant buy anything why ?
if i changed my account to saudi arabia all of my apps i bought is still mine or gone , and my 50 dollars will gone ?
iPhone 6, iOS 8.1.2
By 'cant buy anything' you mean ... ?
If you are in Saudi Arabia then you can only use the Saudi store, using any other country's store will be a violation of the store's terms. You can ask iTunes Support to remove the balance from your account so that you put your real address on your account : http://www.apple.com/support/itunes/contact/
You won't lose anything downloaded into your iTunes library, or on your phone or backup of your downloads/library, when you change country.