QB Issue Resolution:
When you receive payments enter the actual amount paid, QB will ask if you want to refund or keep as a credit.
Resolution for Issue 'A Customer paid by mistake; How do I apply that amount to the customer as credit?' available: Yes (Solved).
Source: Intuit Community forum.
A Customer paid by mistake; How do I apply that amount to the customer as credit?: this issue or error code is a known issue in Quickbooks Online (QBO) and/or Quickbooks. Support for this issue is available either by self-service or paid support options. Experts are available to resolve your Quickbooks issue to ensure minimal downtime and continue running your business. First try to resolve the issue yourself by looking for a resolution described below. If it is a complex issue or you are unable to solve the issue, you may contact us by clicking here or by using other support options.Support for Customer
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Error Recovery for Customer [Canada]
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