Formal — to staff
Vending · Machine
You
この自動販売機、お金だけ取られて商品が出てきません。
このじどうはんばいき、おかねだけとられてしょうひんがでてきません。
This vending machine took my money, but the product didn't come out.
Romaji: Kono jidōhanbaiki, okane dake torarete shōhin ga dete kimasen. / Reply Romaji: Mōshiwake gozaimasen. Dochira no jidōhanbaiki deshō ka? Suguni kakunin shite henkin itashimasu.
Reply
申し訳ございません。どちらの自動販売機でしょうか？すぐに確認して返金いたします。
もうしわけございません。どちらのじどうはんばいきでしょうか？すぐに確認してへんきんいたします。
I apologize. Which vending machine was it? We will check immediately and issue a refund.
Gesture & etiquette
Point towards the vending machine and make a 'no product' gesture (e.g., empty hands).
If a staff member is not immediately available, look for a contact number on the vending machine itself. Be prepared to explain the location and exact machine.