If you need to reach Vantiv by phone for support with your Merchant account, you'll want to call this number: 800-846-4472
If you can get your Merchant ID or Terminal ID together before you call it will help their support team load your account.
If you are calling to request assistance refunding a customer, you'll want to try to get the following information together:
Customer Name
Order Date
Order Amount, Invoice / Order Number
Last 4 Digits of the card on file
The amount you wish to refund.
You can also email that information to ics@mercurypay.com and their Internet Customer Service team will process your request as soon as possible.