I work in the industry. I can help a little. Understand that the first people you talk to have no real ability to control the situation. It is on you to take charge of it. You will need to repeat yourself a lot. And you need to tell them exactly what you need. And you need to insist on them escalating if they cannot get it for you. If you aren't happy? Escalate again and tell them. Ultimately the other person on the phone is just a bottom tier employee with no control in most situations. I know. That's me.