Where can I get a replacement carbonating tube?

Review the ifixit guide and answers given in previous threads. If parts cannot be purchased from sodastream then ebay and amazon may have aftermarket sellers of parts. My guess is sodastream frowns on diy repairs, partly due to liability issues in case of diy accidents and attempts to blame sodastream while restricting repairs to products under warranty. One reply mentions 800 psi of pressure exploding with a diy repair. High pressure operation should never be overlooked when attempts at home repairs are made.