Do you allow your browser to save inputs such as email addresses you put into forms? If yes, maybe you could find where the browser stores this info and check the email address.

As just one data point, I can confirm that they do send a confirmation message when they receive an order. But you probably already have heard this from others. One way to get their attention would be to get your bank to reverse the transfer, if they can possibly do that, which they might, given the circumstances. Of course that risks resetting your timeline.

Also check your deleted emails folder (since you didn't mention this). BTW three weeks is not a long time when it comes to waiting for Starlink. I waited a year.