Hello, @HelenP.
I'd like to help you how to record the refund from CRA to clear out the negative amount.
You can enter it as a deposit posted to the income tax expense account. Just go to your Banking menu and select Make Deposit. Enter all the necessary details on the deposit screen.
You can also refer to this related answer from one of our Community backers: https://quickbooks.intuit.com/learn-support/en-ca/employees-and-payroll/how-do-we-record-a-corporate....
Also, if you may need to process a sales tax adjustment, you can refer to this article for the steps: Process sales tax adjustment.
Let me know if you have follow-up questions with the process. I'll be here to help.