Changing billing address and PO

I truly love Adobe and its amazing products but my god, never be in a position where you need to change the billing address and PO. Finally managed to change the address (i'll wait till the updated invoice comes through as the correct address was already in the system) and then told I can't change the PO number?! Thing is its taken me this long to get this far, we're overdue on payment and the company I work for won't accept the invoice without the new PO!!!!

Has anyone gone through this and if so, how did you get it sorted?