Correctly categorising the refund will adjust the overall expense previously reported in your account, MG1124.
Refunds from your merchants are recorded as an Income-type transaction. Be sure to select the same category used for the original expense. This ensures the total expense for that category is adjusted appropriately.

I recommend consulting with your accountant to ensure the refund is categorised accurately. You can also refer to the article, Understanding allowable and disallowable expenses, for more detailed information on expense categories.
Feel free to reach out if you need further assistance.