récupérer sonneries acheté

If you are saying that they didn't download when you bought them, and they are not in the Downloads tab in the iTunes store app on your phone waiting to download, then you could try contacting iTunes Support via this link : 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

Or try the 'report a problem' from your purchase history on your computer's iTunes : log into your account via the Store > View Account menu option, and there should be a Purchase History section with a 'see all' link to the right of it, find those ringtones and use the 'report a problem' link.

If you are asking whether you can re-download them because they are no longer on your phone, then ringtones are currently a one-time only download from the store. Do you have copies of them in the Tones section of your computer's iTunes library or on your backup of your downloads ? If not, and if they are still in the store, then you could try contacting iTunes Support and see if they will grant you a re-download - you can use the same contact link as above.