Contact your credit card company. Since this issue is more complex, call the company rather than trying to work through the website. Locate the card company's customer service number. You'll find it on the back of your credit card, or on your card statement.
The company's automated phone line will take you through a series of prompts. Have your credit card and information about the purchase with you when you call.
Your account may have a password ***** user ID associated with your card. Enter that information when you're prompted.
You may be asked several security questions, so that the associate on the line can identify you. Answer those questions, based on the answers you provided when you set up your account.
Provide the vendor name, date, dollar amount, and the item purchased. Explain the matter and ask your card company if they can withhold payment and investigate the matter.
If the credit card company withholds the payment, ask them to email you documentation.
Let me know if you need any information from my end on this.