warranty question

[Road Angel A]

New belt rollers & tensioners, would these things generally not be under warranty? I bought GT2 with less than 5k miles on the clock, just about 2 months ago, a week ago I needed to replace these items: cost £795 and found out not on the dealers warranty (not a Porsche warranty)....Porsche did tell me it would have been covered under their own warranty so next year I think I will be purchasing a Porsche warranty on the GT2.