Hi @lauramark,
This is certainly possible using our?Professional extension. This extension includes three new document types: Proforma invoice, Receipt and?Credit note. The last one?will?allow you to create credit notes to your?canceled or partially refunded orders?after creating a refund. See?Creating a refund / credit note.
Please note we follow GAAP (Generally Accepted Accounting Principles) which means that administrative changes should be documented separately. This means that an original invoice should never be modified by a refund. In most countries (at least in the EU) this is even considered fraudulent (and illegal). We have chosen to follow this in both the free and the paid extension.
I explain this to clarify that if you make a partial or full refund for an order, the invoice will not be affected, but a new credit note will be created for that.
Do note that providing help or answer pre-sale questions for paid plugins is forbidden in these forums (see), therefore, please contact us at?[email protected], if you have more questions related this extension.