This happened to me one time and the bank could retrieve it. I never reported a missing card so I could access on line banking. Transferred funds to my visa card and only pulled money from machines attached to a bank. I eventually opened a Thai bank account and use Wise to transfer funds. I needed to be in Canada to set up my Wise account. It was a very good decision.
I've actually had 3 short over stays, but never received stamp. The longest was 3 days, I told them immigration only gave me 57 days on my 60 day visa, I paid the over stay and everyone was happy.
Your going to be turned away at the airport in Canada. Air Canada is particularly strict with this. I have an itinerary longer than my visa and it's going to take me some persuading. Plan b is to book a flight out of Thailand.
The template for the visa application has flaws in it I discovered second time around. I messed up mine once and did it a second time. Still waiting now over a week. If you enter two documents into an upload it over writes the first one. It's seems feels a scam.
Depending on the airline. I've had trouble with this leaving Canada and got lucky when I convinced a supervisor I can change my visa in Thailand and or apply for extensions. Having a passport full of visas and extentions was helpful.
The template for the Thai evisa is a joke. It's been made to be a cash cow. It's difficult to achieve for the average person and many will fail. When you adding more than one document to an upload it overwrites the previous document. I had to put the documents into a word document then convert it into a PDF format and upload. Many would not have the computer skills to do this. I made an error on the date of issue of my passport? No idea how I could have screwed that up. So I've paid again and I wait.
I'm following the advice of a moderator on the Facebook page Thailand Visa Advice and not this group. An added hurdle is flying out of Canada to Thailand with a longer flight itinerary than your visa, airlines often turn people away. If you have a visa you obtained with the flight itinerary, then you have a good chance of convincing them to let you go. I've experience this and know of others who have too. So it's a little bigger than just covid extensions.