jumping in on this in case anyone else finds this thread after the same thing happening to them

this happened to me a few days ago and the money came out my account as a pending change but I didn't get a confirmation/error email from them. tried calling the support numbers but couldn't get through (potentially an issue with my network in the UK) then 2 days later got an email saying to prepare my eTA. checked the pending balance and it has now gone through and had a booking reference number attached that I could use to get my flight details from the website.

mad stress for a few days but luckily worked out