I was wondering y I have been charged several times for the same app wen I have not maid the purchases

We are fellow users here on these forums, we won't know what you've bought.

You, and nobody else who has access to your account or devices, haven't made multiple in-app purchases in the app ?

If not then try contacting iTunes Support (they may want the order numbers from the account's purchase history) : http://www.apple.com/support/itunes/contact/ - click on Contact iTunes Store Support on the right-hand side of the page, then Purchases, Billing & Redemption