Formal — to staff
Vending · Machine · Shopping
You
すみません、この自動販売機がお札を使えなくて。両替できますか？
すみません、このじどうはんばいきがおさつをつかえなくて。りょうがえできますか？
Excuse me, this vending machine doesn't accept bills. Can I get change?
Romaji: Sumimasen, kono jidōhanbaiki ga osatsu o tsukaenakute. Ryōgae dekimasu ka? / Reply Romaji: Hai, nan'ensatsu o nan'endama ni shimasu ka? / Ainiku, koko de wa ryōgae dekimasen.
Reply
はい、何円札を何円玉にしますか？（状況による） / あいにく、ここでは両替できません。
はい、なんえんさつをなんえんだまにしますか？／あいにく、ここではりょうがえできません。
Yes, what denomination bill would you like changed into what denomination coins? (Depends on situation) / Unfortunately, we cannot provide change here.
Gesture & etiquette
Point to the vending machine and show the large bill.
Do not expect all shops to provide change, especially small businesses. It's often easier at larger stores or train stations.