Unfortunately, you cannot cancel pending transactions. It would be great to have a magic button that allows you to cancel transactions, but there is no such button. If you see a debit transaction you don’t recognize, call Wells Fargo customer support and dispute it. You cannot cancel or dispute a pending transaction on credit card accounts. You should first wait till the transaction is posted and then can dispute it. However, Wells Fargo will recommend you contact the merchant first. Customer service cannot help you if you initiate the transaction on your own. You cannot cancel a pending transaction with Wells Fargo.