I try to parchase but iTunes block me what can i do

What do you mean 'iTunes block me', if you are getting an error message then what does it say ?

If you are getting a message to contact iTunes Support then you will have to do so (these are user-to-user forums) :

- go to http://www.apple.com/support/itunes/ww

- click on your country's flag

- click on the Contact Support at the bottom of the left-hand column

- click on Contact iTunes Store Support on the right-hand side of the page

- then Purchases, Billing & Redemption

If it's a different problem ... ?

You are using the above steps to contact them ? If it's been more than 48 hours since you contacted them (you've checked the spam folder as well as the inbox on your email account ?) then contact them again