The OP has contacted me via PM with a request to post the messages below, as it appears they are blocked from adding further replies within 24 hours with a new account.
"Subject: Credit Card Number Ending in XXXX
Recently, you asked us about the transaction billed to your CIBC credit card account for $XXX.xx by KLM AIRLINE XXXXXXXXXXX, on XXXXXXX, 2020. We've begun our investigation.
Temporary credit given while investigating
Based on the information you have provided, we have applied a temporary credit of $XXX.xx to your account. You will see it on your next statement. In addition, we will also reverse any applicable interest charges related to the disputed amount.
What happens next?
Credit card disputes can take up to 100 days to resolve with the merchant's bank, and we appreciate your patience. If the merchant provides us with evidence that the transaction is valid, we will send you a copy of this documentation. We will then have to re-debit your credit card account for the amount of the transaction plus any applicable interest charges. This amount will appear as an amount owing on your next statement.
For more information
It is always a good idea to keep an eye on your credit card purchases. To learn more about what to do for a transaction that you do not believe is valid, or for information about disputed transactions, please visit our website at www.xxxxxxxxxxxxxxxxxx.
We're always here to help
Thank you for your patience while we investigate this matter for you..."
In answer to your question, the rebooked return flight from AMS to YYZ was reticketed by KLM. My wife received our travel documents today from KLM by email.
My guess would be that the reinstated ticket was an automated process. I would keep trying to contact them to explain that you have received the chargeback and that the AMS-YYZ flight is of no use to you. With four weeks to go, hopefully a human being will see your message in time. That is the extent of the advice I can offer... Maybe someone else can pitch in on the odds of the chargeback getting reversed, as I have no experience with them.