Sent emails not being Delivered.

Been dealing with this for 3 days. All I get is the run around. Told that I have to wait to a tier 2/3 person to “contact me” as there is no way to reach them. Been told that my sent emails are “stuck” in their system and no one from level 1 security to regular customer service can help. And over and over they keep asking the same frustrating questions after repeatedly telling them I’ve already been informed that the issue is on their end. Absolutely terrible customer, I won’t be remaining one.