YOU SAID:

the watermelon is at the store so get it from the store

INTO JAPANESE

スイカは店にあるので店から入手してください

BACK INTO ENGLISH

Watermelon is in the store so please get it from the store

INTO JAPANESE

スイカは店内にありますので、お店から入手してください

BACK INTO ENGLISH

Watermelons are in the store, so please get them from the store.

INTO JAPANESE

スイカは店内にありますので、お店から入手してください。

BACK INTO ENGLISH

Watermelons are in the store, so please get them from the store.