Your returns policy is 30 days.
As long as the buyers received the item less than 30 days ago, they are allowed to ask to return them.
Because you are a business seller, you should be able to make a deduction if the items are not received in the same condition.
"There are two ways to be fooled. One is to believe what isn't true; the other is to refuse to believe what is true.”
Søren Kierkegaard, Danish philosopher (1813 - 1855)
