Can't upgrade email quota

I have followed the steps exactly in order to upgrade my email storage but I keep getting the message in red letters that I'm not eligible for an upgrade.  I have tried logging out and logging back in and it is still giving me the same message.  At this time I can't receive any emails because my inbox is full.  And when I try to delete emails it seems they are not deleting as my inbox still shows it is 100% full.  Please help!!