Is it possible to do a quantity based credit for usage?

Summary:

Is it possible to do a quantity based credit for usage or alternatively, how do we reduce the value of the revenue recognised via revenue management?

Content (required):

Where a usage was charged incorrectly on the final period, it is possible to raise a credit memo which sorts the change to the customer but this does not seem to reduce the value of revenue recognised via Revenue Management.

How is it possible to address this issue?

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