Do re-check the email you received, seems a bit early if you only fly Sunday?
If it was successful, I believe either you get a confirmation email that you were charged, or you get a notification that your bid was accepted but your credit balance was not sufficient / credit card could not be charged with the option to change your payment method.
(If it failed, you would just get a non-acceptance email.)
For the trip earlier this month, I got a notification email ~5 days before the flight that I needed to confirm my credit limit was sufficient
in case my bid was successful, a few days before they actually triggered the check. Then I got an email on the actual success / failure of such a bid at around the T-50hr mark.
Below starting text from the ‘Check your limit’ email:
Originally Posted by MHupgrade | Credit/Debit Card Limit
Dear ,
Thank you for choosing Malaysia Airlines and placing your offer. Please ensure that your credit card limit or debit card balance is sufficient for your MHupgrade offer of total CUR ###.
We are only able to process your offer if your credit card limit or debit card balance is sufficient between 72 to 24 hours before your flight departure.