Hello there, @IMCB. I'd be happy to share with you the steps on how you can add customers and vendors with the same name in QuickBooks. 

QuickBooks Desktop (QBDT) won't allow you to add customers and vendors using the same name. This is to avoid any misinterpretation that could affect your overall accounting data. As a workaround, you can add a special character or digits to the name to save it. 

For example:

• ClientC- you add C at the end of the name which indicates that this is a customer.
• ClientV- you add V at the end of the name to tell that this is a vendor.

Then, to guide you in recording a refund for your customer, here's the article that you can open for the detailed steps: Give your customer a credit or refund in QuickBooks Desktop for Windows.

Also, it's recommended to create a backup copy first before doing any changes to your company file. This is to ensure you have the original details that you can restore at any time in case of data loss or damage.

Stay in touch if there's anything else you need about adding names or processing refunds for your customers in QBDT. I go your back. Have a good one.