If you have spent hours chatting with five different teams you have probably already tried all the obvious things numerous times. But just in case, here are some things to try again:
Try starting over with a different browser, and entering your credentials manually rather than relying on your browser to remember your form data.
Are you using the correct eBay username? If you are trying to sign in to an account with a different username, the security emails will be sent to someone else, not you.
Are you absolutely sure you are checking the correct email account for that eBay account? Check your other email accounts just in case. Check your spam folder. If your mail inbox has an option to view all mail, try that in case a filter rule is sending the message somewhere obscure.
Is it possible someone has hijacked your account and changed your email address? That would certainly prevent you from getting those verification emails.
Do you have the option to have the security code sent as a text instead of an email? Have you tried resetting your password? Tried signing in using your email address instead of your username? Tried signing in using a social media account if one is linked to your eBay account? Tried signing in via the app? Or tried using the app to link a social media account and then signing in that way on a desktop?
Have you tried making a purchase using the zero feedback account you are currently signed in to the community discussion boards with? Or making a purchase as a guest? Or creating a new account?
