これは保証でカバーされてないの？って英語でなんて言うの？

「なんでこれは買って一週間しか経ってないのに修理費用がかかるのか、保証でカバーされないのか。」＝　I've only had this bike for one week and I already have to pay for repairs. Why isn't this covered by the guarantee? / Why isn't this covered by the guarantee? I've only had it for one week so I shouldn't have to pay for repairs. ボキャブラリー only had ～ for one week ＝　一週間しか持っていない already ＝　もう既に repair ＝　修理 pay ＝　払う covered ＝ カバーされる the guarantee ＝　保証 shouldn't have to pay ＝　払わなくていいはず