In either case, you should be able to demand and get an itemized call record of every call placed and received, and only the received calls could be "unpublished." Placed calls should always show the actual digits dialed from your phone.
If they insist on billing you for calls they cannot show you placed, then contact your state's telecommunications regulatory agency to lodge a complaint against Verizon.
The tricky part is that calls to Canada use the same North American Area Code system, so you could be dialing a company and not know you were dialing Canada (or Mexico.)
Canada area codes:
Good thinking. That’s probably it.
Thanks for the useful information!
If I travel to Canada from California and you call me there will it be billed as a call to Canada?
It was 867. The “unpublished” came from me doing a search for the number to check if it had been previously reported as a scam number.