Is the saleswoman who defrauded a buyer and refused to return the money after the deal was not completed sinful?

It is impermissible to sell artificial penises, or to buy them, or to act as an intermediary in such transactions. It is obligatory to return the buyer's money to him and demand that he return the sent merchandise. The seller is not allowed to deduct its price from the buyer's money or to give it as charity on his behalf, because the buyer did not request it and does not want it.