In my experience, Unbelievable incompetent support and systems are brokan in multiple places

I cannot believe that a company this size can be so incompetent. I worked through transferring my contacts ( 40,000+) from a competitor. I had several emails back and forth with them because of technical issues with adding people to the unsubscribe list. We spent a long time setting it up and then I sent the campaign. They stopped it after sending 9,000 emails saying there is "unusual activity in your account". There was no unusual activity - they are all legit. I contacted them via support ticket. They open my support ticket each time I sent it ( I can track their emails) - but they don't reply. I cannot contact them via chat online because it's broken and I cannot even create another ticket because "something went wrong". Unbelievable frustrating and incompetent. What sort of system is this? I believe I will be changing again shortly.