You can hide public questions by heading to:
Web:
Your profile name > Selling > select the item
Then tap on “Remove question” below the question you want to hide.
App:
My Shpock > Selling > select the item
Then tap the 3 dots next to the question you want to remove and tap “Hide”
Remember! If the user is spamming or harassing you, you have the option to block or report them.