Formal — to staff
Vending · Machine
You
すみません、そこの自動販売機、お金を入れても商品が出てこないんですが…
すみません、そこのじどうはんばいき、おかねをいれてもしょうひんがでてこないんですが…
Excuse me, the vending machine over there, it took my money but didn't dispense a product...
Romaji: Sumimasen, soko no jidō-hanbaiki, okane o irete mo shōhin ga dete konai n desu ga... / Reply Romaji: Aa, sochira desu ne. Ichido, henkyaku rebā o tamesaremashita ka? Moshi dame deshita ra, mēkā ni renraku shinai to muzukashii kamo shiremasen.
Reply
ああ、そちらですね。一度、返却レバーを試されましたか？もし駄目でしたら、メーカーに連絡しないと難しいかもしれません。
ああ、そちらですね。いちど、へんきゃくレバーをためされましたか？もしだめでしたら、メーカーにれんらくしないとむずかしいかもしれません。
Oh, that one. Have you tried the refund lever once? If that doesn't work, it might be difficult without contacting the manufacturer.
Gesture & etiquette
Point to the vending machine, perhaps show the coin slot or drink dispenser.
The store might not be responsible for a vending machine not owned by them. Be polite and understand they might not be able to help directly.